TNF receptors, TNF binding proteins and DNAS coding for them

ABSTRACT

DNA sequences coding for a TNF-binding protein and for the TNF receptor of which this protein constitutes the soluble domain. The DNA sequences can be used for preparing recombinant DNA molecules in order to produce TNF-binding protein and TNF receptor. Recombinant TNF-binding protein is used in pharmaceutical preparations for treating indications in which TNF has a harmful effect. With the aid of the TNF receptor or fragments thereof or with the aid of suitable host organisms transformed with recombinant DNA molecules containing the DNA which codes for the TNF receptor or fragments or modifications thereof, it is possible to investigate substances for their interaction with the TNF receptor and/or for their effect on the biological activity of TNF.

This application is a continuation of U.S. appl. Ser. No. 08/383,676,filed Feb. 1, 1995, which is a continuation of U.S. appl. Ser. No.08/153,281, filed Nov. 17, 1993, abandoned, which is a continuation ofU.S. appl. Ser. No. 07/821,750, filed Jan. 2, 1992, abandoned, which isa divisional of appl. Ser. No. 07/511,430, filed Apr. 20, 1990,abandoned, the contents of each of which are incorporated herein byreference.

FIELD OF THE INVENTION

The invention is in the field of recombinant genetics. In particular,the invention relates to a TNF receptor and to a TNF binding proteinproduced by recombinant means.

BACKGROUND OF THE INVENTION

Tumour necrosis factor (TNF-α) was first found in the serum of mice andrabbits which had been infected with Bacillus Calmette-Guerin and whichhad been injected with endotoxin, and was recognized on the basis of itscytotoxic and antitumor properties (Carswell, E. A., et al., Proc. Natl.Acad. Sci. 25: 3666-3670 (1975)). It is produced particularly byactivated macrophages and monocytes.

Numerous types of cells which are targets of TNF have surface receptorswith a high affinity for this polypeptide (Old, L. J., Nature326:330-331 (1987)); it was assumed that lymphotoxin (TNF-β) binds tothe same receptor (Aggarwal, B. B., et al., Nature 318:655-667 (1985);Gullberg, U., et al., Eur. J. Haematol. 39:241-251 (1987)). TNF-α isidentical to a factor referred to as cachectin (Beutler, B., et al.,Nature 316:552-554 (1985)) which suppresses lipoprotein lipase andresults in hypertriglyceridaemia in chronically inflammatory andmalignant diseases (Torti, F. M. et al., Nature 229:867-869 (1985);Mahoney, J. R., et al., J. Immunol. 134:1673-1675 (1985)). TNF-α wouldappear to be involved in growth regulation and in the differentiationand function of cells which are involved in inflammation, immuneprocesses and hematopoieses.

TNF can have a positive effect on the host organism by stimulatingneutrophils (Shalaby, M. R., et al., J. Immunol. 135:2069-2073 (1985);Klebanoff, S. J., et al., J. Immunol. 136:4220-4225 (1986)) andmonocytes and by inhibiting the replication of viruses (Mestan, J., etal., Nature 323:816-819 (1986); Wong, G. H. W., et al., Nature323:819-822 (1986)). Moreover, TNF-α activates the immune defensesagainst parasites and acts directly and/or indirectly as a mediator inimmune reactions, inflammatory processes and other processes in thebody, although the mechanisms by which it works have not yet beenclarified in a number of cases. However, the administration of TNF-α(Cerami, A., et al., Immunol. Today 9:28-31 (1988)) can also beaccompanied by harmful phenomena (Tracey, K. J., et al., Science234:470-474 (1986)) such as shock and tissue damage, which can beremedied by means of antibodies against TNF-α (Tracey, K. J., et al.,Nature 330:662-666 (1987)).

A number of observations lead one to conclude that endogenously releasedTNF-α is involved in various pathological conditions. Thus, TNF-αappears to be a mediator of cachexia which can occur in chronicallyinvasive, e.g. parasitic, diseases. TNF-α also appears to play a majorpart in the pathogenesis of shock caused by gram negative bacteria(endotoxic shock); it would also appear to be implicated in some if notall the effects of lipopoly-saccharides (Beutler B., et al., Ann. Rev.Biochem. 57:505-18 (1988)). TNF has also been postulated to have afunction in the tissue damage which occurs in inflammatory processes inthe joints and other tissues, and in the lethality and morbidity of thegraft-versus-host reaction (GVHR, Transplant Rejection (Piguet, P. F.,et al., Immunobiol. 175:27 (1987)). A correlation has also been reportedbetween the concentration of TNF in the serum and the fatal outcome ofmeningococcal diseases (Waage, A., et al., Lancet ii:355-357 (1987)).

It has also been observed that the administration of TNF-α over alengthy period causes a state of anorexia and malnutrition which hassymptoms similar to those of cachexia, which accompany neoplastic andchronic infectious diseases (Oliff A., et al., Cell 555-63 (1987)).

It has been reported that a protein derived from the urine of feverpatients has a TNF inhibiting activity; the effect of this protein ispresumed to be due to a competitive mechanism at the level of thereceptors (similar to the effect of the interleukin-1 inhibitor(Seckinger, P., et al., J. Immunol. 139:1546-1549 (1987); Seckinger P.,et al., J. Exp. Med., 1511-16 (1988)).

EP-A2 308 378 describes a TNF inhibiting protein obtained from humanurine. Its activity was demonstrated in the urine of healthy and illsubjects and determined on the basis of its ability to inhibit thebinding of TNF-α to its receptors on human HeLa cells and FS 11fibroblasts and the cytotoxic effect of TNF-α on murine A9 cells. Theprotein was purified until it became substantially homogeneous andcharacterized by its N-ending. This patent publication does indeedoutline some theoretically possible methods of obtaining the DNA codingfor the protein and the recombinant protein itself; however, there is noconcrete information as to which of the theoretically possible solutionsis successful.

SUMMARY OF THE INVENTION

The invention relates to DNA coding for a TNF receptor protein or afragment thereof. In particular, the invention relates to DNA coding forthe TNF receptor protein having the formula

ATG GGC CTC TCC ACC GTG CCT GAC CTG CTG CTG CCA CTG GTGCTC CTG GAG CTG TTG GTG GGA ATA TAC CCC TCA GGG GTT ATTGGA CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA GAT AGTGTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCGATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AATGAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGTGAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CACTGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTGGAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGCTGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTTTTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTGCAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGCCAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGTAGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTACCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACCACA GTG CTG TTG CCC CTG GTC ATT TTC TTT GGT CTT TGC CTTTTA TCC CTC CTC TTC ATT GGT TTA ATG TAT CGC TAC CAA CGGTGG AAG TCC AAG CTC TAC TCC ATT GTT TGT GGG AAA TCG ACACCT GAA AAA GAG GGG GAG CTT GAA GGA ACT ACT ACT AAG CCCCTG GCC CCA AAC CCA AGC TTC AGT CCC ACT CCA GGC TTC ACCCCC ACC CTG GGC TTC AGT CCC GTG CCC AGT TCC ACC TTC ACCTCC AGC TCC ACC TAT ACC CCC GGT GAC TGT CCC AAC TTT GCGGCT CCC CGC AGA GAG GTG GCA CCA CCC TAT CAG GGG GCT GACCCC ATC CTT GCG ACA GCC CTC GCC TCC GAC CCC ATC CCC AACCCC CTT CAG AAG TGG GAG GAC AGC GCC CAC AAG CCA CAG AGCCTA GAC ACT GAT GAC CCC GCG ACG CTG TAC GCC GTG GTG GAGAAC GTG CCC CCG TTG CGC TGG AAG GAA TTC GTG CGG CGC CTAGGG CTG AGC GAC CAC GAG ATC GAT CGG CTG GAG CTG CAG AACGGG CGC TGC CTG CGC GAG GCG CAA TAC AGC ATG CTG GCG ACCTGG AGG CGG CGC ACG CCG CGG CGC GAG GCC ACG CTG GAG CTGCTG GGA CGC GTG CTC CGC GAC ATG GAC CTG CTG GGC TGC CTGGAG GAC ATC GAG GAG GCG CTT TGC GGC CCC GCC GCC CTC CCGCCC GCG CCC AGT CTT CTC AGA TGA

or a fragment or a degenerate variant thereof.

The invention also relates to DNA coding for a secretable TNF-bindingprotein having the formula

R²  GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAAAAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TACTTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGCAGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CACCTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATGGGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACCGTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGTGAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AATGGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTGTGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGTGTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAGTTG TGC CTA CCC CAG ATT GAG AAT

wherein R² is optionally absent or represents DNA coding for apolypeptide which can be cleaved in vivo; or a degenerate variantthereof.

The invention also relates to nucleic acid which hybridizes with the DNAof the invention under conditions of low stringency and which codes fora polypeptide having the ability to bind TNF.

The invention also relates to a recombinant DNA molecule, comprising theDNA molecules of the invention.

The invention also relates to host cells transformed with therecombinant DNA molecules of the invention.

The invention also relates to the substantially pure recombinant TNFreceptor polypeptides of the invention. In particular, the inventionrelates to a TNF receptor of formula

met gly leu ser thr val pro asp leu leu leu pro leu valleu leu glu leu leu val gly ile tyr pro ser gly val ilegly leu val pro his leu gly asp arg glu lys arg asp serval cys pro gln gly lys tyr ile his pro gln asn asn serile cys cys thr lys cys his lys gly thr tyr leu tyr asnasp cys pro gly pro gly gln asp thr asp cyc arg glu cysglu ser gly ser phe thr ala ser glu asn his leu arg hiscys leu ser cys ser lys cys arg lys glu met gly gln valglu ile ser ser cys thr val asp arg asp thr val cys glycys arg lys asn gln tyr arg his tyr trp ser glu asn leuphe gln cys phe asn cys ser leu cys leu asn gly thr valhis leu ser cys gln glu lys gln asn thr val cys thr cyshis ala gly phe phe leu arg glu asn glu cys val ser cysser asn cys lys lys ser leu glu cys thr lys leu cys leupro gln ile glu asn val lys gly thr glu asp ser gly thrthr val leu leu pro leu val ile phe phe gly leu cys leuleu ser leu leu phe ile gly leu met tyr arg tyr gln argtrp lys ser lys leu tyr ser ile val cys gly lys ser thrpro glu lys glu gly glu leu glu gly thr thr thr lys proleu ala pro asn pro ser phe ser pro thr pro gly phe thrpro thr leu gly phe ser pro val pro ser ser thr phe thrser ser ser thr tyr thr pro gly asp cys pro asn phe alaala pro arg arg glu val ala pro pro tyr gln gly ala asppro ile leu ala thr ala leu ala ser asp pro ile pro asnpro leu gln lys trp glu asp ser ala his lys pro gln serleu asp thr asp asp pro ala thr leu tyr ala val val gluasn val pro pro leu arg trp lys glu phe val arg arg leugly leu ser asp his glu ile asp arg leu glu leu gln asngly arg cys leu arg glu ala gln tyr ser met leu ala thrtrp arg arg arg thr pro arg arg glu ala thr leu glu leuleu gly arg val leu arg asp met asp leu leu gly cys leuglu asp ile glu glu ala leu cys gly pro ala ala leu propro ala pro ser leu leu arg

or a fragment thereof which binds to TNF.

The invention also relates to the TNF binding protein of the formula

asp serp val cys pro gln gly lys tyr ile his pro gln asnasn ser ile cys cys thr lys cys his lys gly thr tyr leutyr asn asp cys pro gly pro gly gln asp thr asp cys argglu cys glu ser gly ser phe thr ala ser glu asn his leuarg his cys leu ser cys ser lys cys arg lys glu met glygln val glu ile ser ser cys thr val asp arg asp thr valcys gly cys arg lys asn gln tyr arg his tyr trpser glu asn leu phe gln cys phe asn cys ser leu cys leuasn gly thr val his leu ser cys gln glu lys gln asn thrval cys thr cys his ala gly phe phe leu arg glu asn glucys val ser cys ser asn cys lys lys ser leu glu cys thrlys leu cys leu pro gln ile glu asn

or a functional derivative or fragment thereof having the ability tobind TNF.

The invention also relates to a process for preparing a recombinant TNFreceptor protein, or a functional derivative thereof which is capable ofbinding to TNF, comprising cultivating a host cell of the invention andisolating the expressed recombinant TNF receptor protein.

The invention also relates to pharmaceutical compositions comprising aTNF receptor protein, or a functional derivative or fragment thereof,and a pharmaceutically acceptable carrier.

The invention also relates to a method for ameliorating the harmfuleffects of TNF in an animal, comprising administering to an animal inneed of such treatment a therapeutically effective amount of a TNFreceptor polypeptide, or fragment thereof which binds to TNF.

The invention also relates to a method for the detection of TNF in abiological sample, comprising contacting said sample with an effectiveamount of a TNF receptor polypeptide, or fragment thereof which binds toTNF, and detecting whether a complex is formed.

DESCRIPTION OF THE FIGURES

FIGS. 1A-1C depict the complete nucleotide sequence of 1334 bases of thecDNA insert of λTNF-BP15 and pTNF-BP15.

FIG. 2 depicts a hydrophobicity profile which was produced using the MacMolly program.

FIGS. 3A-3B depict the scheme used for the construction of plasmidpCMV-SV40.

FIGS. 4A-4B depict the scheme used for the construction of plasmidpSV2gptDHFR Mut2.

FIGS. 5A-5B depict the scheme used for the construction of plasmidspAD-CMV1 and pAD-CMV2.

FIGS. 6A-6E depict the full nucleotide sequence of the 6414 bp plasmidpADCMV1.

FIG. 7 depicts the structure of the plasmids designated pADTNF-BP,pADBTNF-BP, pADTNF-R and pADBTNF-R.

FIGS. 8A-8B depict the complete nucleotide sequence of raTNF-R8.

FIGS. 9A-9B depict the complete coding region for human TNF-R inlTNF-R2.

FIG. 10 depicts an autoradiogram showing a singular RNA band with alength of 2.3 kb for the human TNF receptor.

BACKGROUND OF THE INVENTION

In preliminary tests for the purposes of the present invention (seeExamples 1-4), a protein was identified from the dialyzed urine ofuraemia patients, and this protein inhibits the biological effects ofTNF-α by interacting with TNF-α to prevent it from binding to its cellsurface receptor (Olsson I., et al., Eur. J. Haematol. 41:414-420(1988)). This protein was also found to have an affinity for TNF-β.

The presence of this protein (hereinafter referred to as TNF-BP) inconcentrated dialyzed urine was detected by competition with the bindingof radioactively labelled recombinant TNF-α to a subclone of HL-60cells, by measuring the influence of dialyzed urine on the binding of¹²⁵I-TNF-α to the cells. The binding tests carried out showed a dosagedependent inhibition of TNF-α binding to the cells by concentrateddialyzed urine (the possible interpretation that the reduction inbinding observed might be caused by any TNF-α present in the urine or byTNF-β competing for the binding, was ruled out by the discovery that thereduction in binding could not be remedied by the use of TNF-α and TNF-βantibodies).

Analogously, in preliminary tests for the purposes of the presentinvention, it was demonstrated that TNF-BP also shows an affinity forTNF-β, which is about {fraction (1/50+L )} of its affinity for TNF-α.

Gel chromatography on Sephacryl 200 showed that a substance in the urineand serum of dialysis patients and in the serum of healthy subjectsforms a complex with recombinant TNF-α with a molecular weight of about75,000.

TNF-BP was concentrated 62 times from several samples of dialyzed urinefrom uraemia patients by partial purification using pressureultrafiltration, ion exchange chromatography and gel chromatography.

The preparations obtained were used to detect the biological activity ofTNF-BP by inhibiting the growth-inhibiting effect of TNF-α on HL-60-10cells. TNF-BP was found to have a dosage dependent effect on thebiological activity of TNF-α. The binding characteristics of cells wasalso investigated by pretreatment with TNF-BP and an exclusivecompetition binding test. It was shown that pretreatment of the cellswith TNF-BP does not affect the binding of TNF-α to the cells. Thisindicates that the effect of TNF-BP is not based on any binding to thecells and competition with TNF-α for the binding to the receptor.

The substantially homogeneous protein is obtained in highly purifiedform by concentrating urine from dialysis patients by ultrafiltration,dialyzing the concentrated urine and concentrating it four-fold in afirst purification step using DEAE sephacel chromatography. Furtherconcentration was carried out by affinity chromatography usingsepharose-bound TNF-α. The final purification was carried out usingreverse phase chromatography (FPLC).

It was shown that the substantially highly purified protein inhibits thecytotoxic effect of TNF-α on WEHI 164 clone 13 cells (Olsson et al.,Eur. J. Haematol. 42:270-275 (1989)).

The N-terminal amino acid sequence of the substantially highly purifiedprotein was analyzed. It was found to beAsp-Ser-Val-Xaa-Pro-Gln-Gly-Lys-Tyr-Ile-His-Pro-Gln (main sequence); thefollowing N-terminal sequence was detected in traces:Leu-(Val)-(Pro)-(His)-Leu-Gly-Xaa-Arg-Glu (subsidiary sequence). Acomparison of the main sequence with the N-terminal sequence of theTNF-inhibiting protein disclosed in EP-A2 308 378 shows that the twoproteins are identical.

The following amino acid composition was found, given in mols of aminoacid per mol of protein and in mol-% of amino acid, measured as theaverage of 24-hour and 48-hour hydrolysis:

Mol of amino acid/ Mol % mol of protein amino acid Asp + Asn 27.5 10.9 Thr 15.8 6.3 Ser 20.7 8.2 Glu + Gln 35.0 13.8  Pro  9.5 3.8 Gly 16.0 6.3Ala  4.2 1.7 Cys 32.3 12.8  Val 10.8 4.3 Met  1.1 0.4 Ile  7.0 2.8 Leu20.2 8.0 Tyr  6.1 2.4 Phe  8.1 3.2 His 11.1 4.4 Lys 15.7 6.2 Arg 11.84.7 Total 252.9  100   

A content of glucosamine was detected by amino acid analysis. Theresults of an affinoblot carried out using Concanavalin A and wheatgermlectin also showed that TNF-BP is a glycoprotein.

The substantially homogeneous protein was digested with trypsin and theamino acid sequences of 17 of the cleavage peptides obtained weredetermined. The C-ending was also analyzed.

TNF-BP obviously has the function of a regulator of TNF activity withthe ability to buffer the variations in concentration of free,biologically active TNF-α. TNF-BP should also affect the secretion ofTNF by the kidneys because the complex formed with TNF, the molecularweight of which was measured at around 75,000 by gel permeationchromatography on Sephadex G 75, is obviously not retained by theglomerulus, unlike TNF. The TNF-BP was detected in the urine of dialysispatients as one of three main protein components which have an affinityfor TNF and which are eluted together with TNF-BP from the TNF affinitychromatography column. However, the other two proteins obviously bind ina manner which does not affect the binding of TNF-α to its cell surfacereceptor.

The results obtained regarding the biological activity of TNF-BP, inparticular the comparison of the binding constant with the bindingconstant described for the TNF receptor (Creasey, A. A., et al., Proc.Natl. Acad. Sci. 84:3293-3297 (1987)), provided a first indication thatthis protein might be the soluble part of a TNF receptor.

In view of its ability to inhibit the biological activity of TNF-α andTNF-β, the TNF binding protein is suitable for use in cases where areduction in the TNF activity in the body is indicated. Functionalderivatives or fragments of the TNF binding protein with the ability toinhibit the biological activity of TNF are also suitable for use in suchcases.

Covalent modifications of the TNF binding proteins of the presentinvention are included within the scope of this invention. Variant TNFbinding proteins may be conveniently prepared by in vitro synthesis.Such modifications may be introduced into the molecule by reactingtargeted amino acid residues of the purified or crude protein with anorganic derivatizing agent that is capable of reacting with selectedside chains or terminal residues. The resulting covalent derivatives areuseful in programs directed at identifying residues important forbiological activity.

Cysteinyl residues most commonly are reacted with α-haloacetates (andcorresponding amines), such as chloroacetic acid or chloroacetamide, togive carboxymethyl or carboxyamidomethyl derivatives. Cysteinyl residuesalso are derivatized by reaction with bromotrifluoroacetone,α-bromo-β-(5-imidozoyl)propionic acid, chloroacetyl phosphate,N-alkylmaleimides, 3-nitro-2-pyridyl disulfide, methyl 2-pyridyldisulfide, p-chloromercuribenzoate, 2-chloromercuri-4-nitrophenol, orchloro-7-nitrobenzo-2-oxa-1,3-diazole.

Histidyl residues are derivatized by reaction with diethylprocarbonateat pH 5.5-7.0 because this agent is relatively specific for the histidylside chain. Para-bromophenacyl bromide also is useful; the reaction ispreferably performed in 0.1 M sodium cacodylate at pH 6.0.

Lysinyl and amino terminal residues are reacted with succinic or othercarboxylic acid anhydrides. Derivatization with these agents has theeffect of reversing the charge of the lysinyl residues. Other suitablereagents for derivatizing α-amino-containing residues includeimidoesters such as methyl picolinimidate; pyridoxal phosphate;pyridoxal; chloroborohydride; trinitrobenzenesulfonic acid;0-methylissurea; 2,4 pentanedione; and transaminase-catalyzed reactionwith glyoxylate.

Arginyl residues are modified by reaction with one or severalconventional reagents, among them phenylglyoxal, 2,3-butanedione,1,2-cyclohexanedione, and ninhydrin. Derivatization of arginine residuesrequires that the reaction be performed in alkaline conditions becauseof the high pK_(a) of the guanidine functional group. Furthermore, thesereagents may react with the groups of lysine as well as the arginineepsilon-amino group.

The specific modification of tyrosyl residues per se has been studiedextensively, with particular interest in introducing spectral labelsinto tyrosyl residues by reaction with aromatic diazonium compounds ortetranitromethane. Most commonly, N-acetylimidizol and tetranitromethaneare used to form 0-acetyl tyrosyl species and 3-nitro derivatives,respectively. Tyrosyl residues are iodinated using ¹²⁵I or ¹³¹I toprepare labeled proteins for use in radioimmunoassay, the chloramine Tmethod described above being suitable.

Carboxyl side groups (aspartyl or glutamyl) are selectively modified byreaction with carbodiimides (R′-N-C-N-R′) such as1-cyclohexyl-3-(2-morpholinyl-(4-ethyl) carbodiimide or 1-ethyl-3 (4azonia 4,4-dimethylpentyl) carbodiimide. Furthermore, aspartyl andglutamyl residues are converted to asparaginyl and glutaminyl residuesby reaction with ammonium ions.

Derivatization with bifunctional agents is useful for crosslinking theTNF binding proteins to water-insoluble support matrixes or surfaces foruse in the method for cleaving TNF binding protein-fusion polypeptide torelease and recover the cleaved polypeptide. Commonly used crosslinkingagents include, e.g., 1,1-bis(diazoacetyl)-2-phenylethane,glutaraldehyde, N-hydroxysuccinimide esters, for example, esters with4-azidosalicylic acid, homobifunctional imidoesters, includingdisuccinimidyl esters such as 3,3′-dithiobis(succinimidylpropionate),and bifunctional maleimides such as bis-N-maleimido-1,8-octane.Derivatizing agents such asmethyl-3-[(p-azidophenyl)dithio]propioimidate yield photoactivatableintermediates that are capable of forming crosslinks in the presence oflight. Alternatively, reactive water-insoluble matrices such as cyanogenbromide-activated carbohydrates and the reactive substrates described inU.S. Pat. Nos. 3,969,287; 3,691,016; 4,195,128; 4,247,642; 4,229,537;and 4,330,440 are employed for protein immobilization.

Glutaminyl and asparaginyl residues are frequently deamidated to thecorresponding glutamyl and aspartyl residues. Alternatively, theseresidues are deamidated under mildly acidic conditions. Either form ofthese residues falls within the scope of this invention.

Other modifications include hydroxylation of proline and lysine,phosphorylation of hydroxyl groups of seryl or theonyl residues,methylation of the a-amino groups of lysine, arginine, and histidineside chains (T. E. Creighton, Proteins: Structure and MoleculeProperties, W. H. Freeman & Co., San Francisco, pp. 79-86 (1983)),acetylation of the N-terminal amine, and, in some instances, amidationof the C-terminal carboxyl groups.

Amino acid sequence variants of the TNF binding proteins can also beprepared by mutations in the DNA. Such variants include, for example,deletions from, or insertions or substitutions of, residues within theamino acid sequence shown in the Figures. Any combination of deletion,insertion, and substitution may also be made to arrive at the finalconstruct, provided that the final construct possesses the desiredactivity (binding to TNF). Obviously, the mutations that will be made inthe DNA encoding the variant must not place the sequence out of readingframe and preferably will not create complementary regions that couldproduce secondary mRNA structure (see EP Patent Application PublicationNo. 75,444).

At the genetic level, these variants ordinarily are prepared bysite-directed mutagenesis of nucleotides in the DNA encoding the TNFbinding proteins, thereby producing DNA encoding the variant, andthereafter expressing the DNA in recombinant cell culture. The variantstypically exhibit the same qualitative biological activity as thenaturally occurring analog.

While the site for introducing an amino acid sequence variation ispredetermined, the mutation per se need not be predetermined. Forexample, to optimize the performance of a mutation at a given site,random mutagenesis may be conducted at the target codon or region andthe expressed TNF binding protein variants screened for the optimalcombination of desired activity. Techniques for making substitutionmutations at predetermined sites in DNA having a known sequence are wellknown, for example, site-specific mutagenesis.

Preparation of a TNF binding protein variant in accordance herewith ispreferably achieved by site-specific mutagenesis of DNA that encodes anearlier prepared variant or a nonvariant version of the protein.Site-specific mutagenesis allows the production of TNF binding proteinvariants through the use of specific oligonucleotide sequences thatencode the DNA sequence of the desired mutation, as well as a sufficientnumber of adjacent nucleotides, to provide a primer sequence ofsufficient size and sequence complexity to form a stable duplex on bothsides of the deletion junction being traversed. Typically, a primer ofabout 20 to 25 nucleotides in length is preferred, with about 5 to 10residues on both sides of the junction of the sequence being altered. Ingeneral, the technique of site-specific mutagenesis is well known in theart, as exemplified by publications such as Adelman et al., DNA 2:183(1983), the disclosure of which is incorporated herein by reference.

As will be appreciated, the site-specific mutagenesis techniquetypically employs a phage vector that exists in both a single-strandedand double-stranded form. Typical vectors useful in site-directedmutagenesis include vectors such as the M13 phage, for example, asdisclosed by Messing et al., Third Cleveland Symposium on Macromoleculesand Recombinant DNA, Editor A. Walton, Elsevier, Amsterdam (1981), thedisclosure of which is incorporated herein by reference. These phage arereadily commercially available and their use is generally well known tothose skilled in the art. Alternatively, plasmid vectors that contain asingle-stranded phage origin of replication (Veira et al., Meth.Enzymol. 153:3 (1987)) may be employed to obtain single-stranded DNA.

In general, site-directed mutagenesis in accordance herewith isperformed by first obtaining a single-stranded vector that includeswithin its sequence a DNA sequence that encodes the relevant protein. Anoligonucleotide primer bearing the desired mutated sequence is prepared,generally synthetically, for example, by the method of Crea et al.,Proc. Natl. Acad. Sci. (USA) 75:5765 (1978). This primer is thenannealed with the single-stranded protein-sequence-containing vector,and subjected to DNA-polymerizing enzymes such as E. coli polymerase IKlenow fragment, to complete the synthesis of the mutation-bearingstrand. Thus, a mutated sequence and the second strand bears the desiredmutation. This heteroduplex vector is then used to transform appropriatecells such as JM101 cells and clones are selected that includerecombinant vectors bearing the mutated sequence arrangement.

After such a clone is selected, the mutated protein region may beremoved and placed in an appropriate vector for protein production,generally an expression vector of the type that may be employed fortransformation of an appropriate host.

Amino acid sequence deletions may generally range from about 1 to 30residues or 1 to 10 residues, and typically are contiguous.

Amino acid sequence insertions include amino and/or carboxyl-terminalfusions of from one residue to polypeptides of essentially unrestrictedlength, as well as intrasequence insertions of single or multiple aminoacid residues. Intrasequence insertions (i.e., insertions within thecomplete hormone receptor molecule sequence) may range generally fromabout 1 to 10 or 1 to 5 residues. An example of a terminal insertionincludes a fusion of a signal sequence, whether heterologous orhomologous to the host cell, to the N-terminus of the TNF bindingprotein to facilitate the secretion of mature TNF binding protein fromrecombinant hosts.

The third group of variants are those in which at least one amino acidresidue in the TNF binding protein, and preferably, only one, has beenremoved and a different residue inserted in its place. Suchsubstitutions preferably are made in accordance with the following Table1 when it is desired to modulate finely the characteristics of a hormonereceptor molecule.

TABLE 1 Original Exemplary Residue Substitutions Ala gly; ser Arg lysAsn gln; his Asp glu Cys ser Gln asn Glu asp Gly ala; pro His asn; glnIle leu; val Leu ile; val Lys arg; gln; glu Met leu; tyr; ile Phe met;leu; tyr Ser thr Thr ser Trp tyr Tyr trp; phe Val ile; leu

Substantial changes in functional or immunological identity are made byselecting substitutions that are less conservative than those in Table1, i.e., selecting residues that differ more significantly in theireffect on maintaining (a) the structure of the polypeptide backbone inthe area of the substitution, for example, as a sheet or helicalconformation, (b) the charge or hydrophobicity of the molecule at thetarget site, or (c) the bulk of the side chain. The substitutions thatin general are expected to those in which (a) glycine and/or proline issubstituted by another amino acid or is deleted or inserted; (b) ahydrophilic residue, e.g., seryl or threonyl, is substituted for (or by)a hydrophobic residue, e.g., leucyl, isoleucyl, phenylalanyl, valyl, oralanyl; (c) a cysteine residue is substituted for (or by) any otherresidue; (d) a residue having an electropositive side chain, e.g.,lysyl, arginyl, or histidyl, is substituted for (or by) a residue havingan electronegative charge, e.g., glutamyl or aspartyl; or (e) a residuehaving a bulky side chain, e.g., phenylalanine, is substituted for (orby) one not having such a side chain, e.g., glycine.

Most deletions and insertions, and substitutions in particular, are notexpected to produce radical changes in the characteristics of the TNFbinding protein. However, when it is difficult to predict the exacteffect of the substitution, deletion, or insertion in advance of doingso, one skilled in the art will appreciate that the effect will beevaluated by routine screening assays. For example, a variant typicallyis made by site-specific mutagenesis of the TNF binding protein-encodingnucleic acid, expression of the variant nucleic acid in recombinant cellculture, and, optionally, purification from the cell culture, forexample, by immunoaffinity adsorption on a polyclonal anti-TNF bindingprotein column (to absorb the variant by binding it to at least oneremaining immune epitope).

The activity of the cell lysate or purified TNF binding protein variantis then screened in a suitable screening assay for the desiredcharacteristic. For example, a change in the binding affinity for TNF orimmunological character of the TNF binding protein, such as affinity fora given antibody, is measured by a competitive type immunoassay. Changesin immunomodulation activity are measured by the appropriate assay.Modifications of such protein properties as redox or thermal stability,hydrophobicity, susceptibility to proteolytic degradation or thetendency to aggregate with carriers or into multimers are assayed bymethods well known to the ordinarily skilled artisan.

TNF-BP (or the functional derivatives, variants, and active fragmentsthereof) may be used for the prophylactic and therapeutic treatment ofthe human or animal body in indications where TNF-a has a harmfuleffect. Such diseases include in particular inflammatory and infectiousand parasitic diseases or states of shock in which endogenous TNFa isreleased, as well as cachexia, GVHR, ARDS (Adult Respiratory DistressSymptom) and autoimmune diseases such as rheumatoid arthritis, etc. Alsoincluded are pathological conditions which may occur as side effects oftreatment with TNF-α, particularly at high doses, such as severehypotension or disorders of the central nervous system.

In view of its TNF binding properties, TNF-BP is also suitable as adiagnostic agent for determining TNF-α and/or TNF-P, e.g., as one of thecomponents in radioimmunoassays or enzyme immunoassays, optionallytogether with antibodies against TNF.

In view of its properties, this protein is a pharmacologically usefulactive substance which cannot be obtained in sufficient quantities fromnatural sources using protein-chemical methods.

There was therefore a need to produce this protein (or related proteinswith the ability to bind TNF) by recombinant methods in order that itcould be made available in sufficient amounts for therapeutic use. Thephrase “ability to bind TNF” within the scope of the present inventionmeans the ability of a protein to bind to TNF-α in such a way that TNF-ais prevented from binding to the functional part of the receptor and theactivity of TNF-α in humans or animals is inhibited or preventedaltogether. This definition also includes the ability of a protein tobind to other proteins, e.g. to TNF-β, and inhibit their effect.

The aim of the present invention was to provide the DNA which codes forTNF-BP, in order to make it possible, on the basis of this DNA, toproduce recombinant DNA molecules by means of which suitable hostorganisms can be transformed, with the intention of producing TNF-BP orfunctional derivatives and fragments thereof.

Within the scope of this objective, it was also necessary to establishwhether TNF-BP is the soluble part of a TNF receptor. This assumptionwas confirmed, thus providing the basis for clarification of thereceptor sequence.

Another objective within the scope of the present invention was toprepare the cDNA coding for a TNF receptor, for the purpose of producingrecombinant human TNF receptor.

The presence of a specific receptor with a high affinity for TNF-α onvarious cell types was shown by a number of working groups. Recently,the isolation and preliminary characterization of a TNF-α receptor wasreported for the first time (Stauber, G. B., et al., J. Biol. Chem.263:19098-19104 (1988)). Since the binding of radioactively labelledTNF-α can be reversed by an excess of TNF-β (Aggarwal, B. B., et al.,Nature 318:655-667 (1985)), it was proposed that TNF-α and TNF-β share acommon receptor. On the other hand, since it was shown that certain celltypes which respond to TNF-α are wholly or partly insensitive to TNF-β(Locksley, R. M., et al., J. Imunol. 139:1891-1895 (1987)), theexistence of a common receptor was thrown into doubt again.

By contrast, recent results on the binding properties of TNF-β toreceptors appear to confirm the theory of a common receptor (Stauber, G.B., et al., J. Biol. Chem. 264:3573-3576 (1989)), and this studyproposes that there are differences between TNF-α and TNF-β in theirinteraction with the receptor or in addition with respect to the eventswhich occur in the cell after the ligand-receptor interaction. Lately,there has been a report of another TNF-binding protein which is presumedto be the soluble form of a different TNF receptor (Engelmann et al., J.Biol. Chem. 265:1531-1536 (1990)). The availability of the DNA codingfor a TNF receptor is the prerequisite for the production of recombinantreceptor and consequently makes it much easier to carry out comparativeinvestigations on different types of cell regarding their TNF-α and/orTNF-β receptors or the reactions triggered by the binding of TNF to thereceptor in the cell. It also makes it possible to clarify thethree-dimensional structure of the receptor and hence provide theprerequisite for a rational design for the development of agonists andantagonists for the TNF activity.

The efforts to solve the problem of the invention started from thefinding that major difficulties are occasionally encountered whensearching through cDNA libraries using hybridizing probes derived fromamino acid sequences of short peptides, on account of the degenerationof the genetic code. In addition, this procedure is made more difficultwhen the researcher does not know in which tissue a particular protein,e.g. TNF-BP, is synthesized. In this case, should the method fail, it isnot always possible to tell with any certainty whether the cause of thefailure was the choice of an unsuitable cDNA library or the insufficientspecificity of the hybridization probes.

Therefore, the following procedure was used according to the inventionin order to obtain the DNA coding for TNF-BP:

The cDNA library used was a library of the fibrosarcoma cell line HS913T which had been induced with TNFα and was present in λ gt11. In orderto obtain λ DNA with TNF-BP sequences from this library, the high degreeof sensitivity of the polymerase chain reaction (PCR (Saiki, R. K.,Science 239:487-491 (1988))) was used. (Using this method it is possibleto obtain, from an entire cDNA library, an unknown DNA sequence flankedby oligonucleotides which have been designed on the basis of known aminoacid partial sequences and used as primers. A longer DNA fragment ofthis kind can subsequently be used as a hybridization probe, e.g. inorder to isolate cDNA clones, particularly the original cDNA clone).

On the basis of the N-terminal amino acid sequence (main sequence) andamino acid sequences of tryptic peptides obtained from highly purifiedTNF-BP, hybridization probes were prepared. Using these probes, a cDNAwhich constitutes part of the cDNA coding for TNF-BP was obtained by PCRfrom the cDNA library HS913T.

This cDNA has the following nucleotide sequence:

CAG GGG AAA TAT ATT CAC CCT CAA AAT AAT TCG ATT TGC TGT ACCAAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCGGGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACAGCC TCA GAA AAC AAC AAG.

This DNA is one of a number of possible variants which are suitable forhybridizing with TNF-BP DNAs or TNF-BP-RNAs (these variants include forexample those DNA molecules which are obtained by PCR amplification withthe aid of primers, wherein the nucleotide sequence does not coincideprecisely with the desired sequence, possibly as a result of restrictionsites provided for cloning purposes or because of amino acids which werenot clearly identified in the amino acid sequence analysis).“TNF-BP-DNAs” and “TNF-BP-RNAs” indicate nucleic acids which code forTNF-BP or related proteins with the ability to bind TNF or which containa sequence coding for such a protein.

TNF-BP-DNAs (or TNF-BP-RNAs) also include cDNAs derived from mRNAs whichare formed by alternative splicing (or these mRNAs themselves). Thephrase “alternative splicing” means the removal of introns, using spliceacceptor and/or splice donor sites which are different from the samemRNA precursor. The mRNAs thus formed differ from one another by thetotal or partial presence or absence of certain exon sequences, and insome cases there may be a shift in the reading frame.

The cDNA (or variants thereof) initially obtained according to theinvention, containing some of the sequence coding for TNF-BP, can thusbe used as a hybridization probe in order to obtain cDNA clonescontaining TNF-BP DNAs from cDNA libraries. It may also be used as ahybridization probe for mRNA preparations, for isolating TNF-BP RNAs andfor producing concentrated cDNA libraries therefrom, for example, toallow much simpler and more efficient screening. A further field ofapplication is the isolation of the desired DNAs from genomic DNAlibraries using these DNAs as hybridization probes.

The DNA defined hereinbefore (or a variant thereof) is capable ofhybridizing with DNAs (or RNAs) which code for TNF-BP or contain thesequence which codes for TNF-BP. Using this DNA as probe, it is alsopossible to obtain cDNAs which code for proteins, the processing ofwhich yields TNF-BP. The term “processing” means the splitting off ofpartial sequences in vivo. This might mean, at the N-terminus the signalsequence and/or other sequences and possibly also at the C-terminus, thetransmembrane and cytoplasmic region of the receptor. Using thishybridization signal it is therefore possible to search through suitablecDNA libraries to look for any cDNA which contains the entire sequencecoding for a TNF receptor (if necessary, this operation may be carriedout in several steps).

According to the invention, the cDNA of the sequence definedhereinbefore, which had been obtained by PCR from the cDNA library ofthe TNF-A induced fibrosarcoma cell line HS913 T (in λ gt11), was usedto search through the cDNA library once more, the lambda DNA was excisedfrom the hybridizing clones, subcloned and sequenced. A 1334 base longcDNA insert was obtained which contains the sequence coding for TNF BP.

Thus, first of all DNAs were prepared, coding for a polypeptide capableof binding TNF, or for a polypeptide in which this TNF binding proteinis a partial sequence. These DNAs also include DNAs of the kind whichcode for parts of these polypeptides.

The complete nucleotide sequence of the longest c D N A insert obtainedis shown in FIGS. 1A-1C.

This nucleotide sequence has a continuous open reading frame beginningwith base 213 up to the end of the 1334 bp long cDNA insert. Since thereis a stop codon (TAG) in the same reading frame 4 codons before thepotential translation start codon ATG (213-215), it was assumed that thestart codon is actually the start of translation used in vivo.

A comparison of the amino acid sequence derived from the nucleotidesequence with the amino acid sequences determined from the aminoterminal end of TNF-BP and tryptic peptides, shows a high degree ofconformity. This means that the isolated cDNA contains the sequencecoding for authentic TNF-BP.

Starting from the N-terminus, the first sequence which shows conformitywith a tryptic cleavage peptide sequence is the sequence from fraction12 (Leu-Val-Pro- . . . ), which had also been obtained as a subsidiarysequence in the analysis of the N-terminus of TNF-BP. This N-terminalleucine corresponds to the 30th amino acid in the cDNA sequence. Sincethe preceding section of 29 amino acids has a strongly hydrophobicnature and TNF-BP is a secreted protein, it can be concluded that these29 amino acids constitute the signal peptide required for the secretionprocess, which is split off during secretion (designated S1-S29 in FIG.1A). The amino acid sequence obtained as the main sequence in theN-terminal analysis of TNF-BP corresponds to the amino acids beginningwith Asp-12 in the cDNA sequence. This aspartic acid group directlyfollows the basic dipeptide Lys-Arg. Since a very large number ofproteins are cleaved proteolytically in vivo after this dipeptide, itcan be assumed that TNF-BP with N-terminal Asp is not formed directly bythe processing of a precursor in the secretion process, but that theN-terminal 11 amino acids are split off from the processed protein at alater time by extracellular proteases. The carboxyterminal end of TNF-BPhad been determined as Ile-Glu-Asn (C-terminal analysis; tryptic peptidefraction 27: amino acids 159-172, tryptic peptide fraction 21: aminoacids 165-172), Asn corresponding to position 172 in the cDNA sequence.

Potential N-glycosylation sites of general formula Asn-Xaa-Ser/Thr, inwhich Xaa may be any amino acid other than proline, are located atpositions 25-27 (Asn-Asn-Ser), 116-118 (Asn-Cys-Ser) and 122-124(Asn-Gly-Thr) of the TNF-BP cDNA sequence. (The fact that Asn-25 isglycosylated is clear from the fact that Asn could not be identified inthe sequencing of the corresponding tryptic cleavage peptide at thissite.)

Analysis of the nucleotide sequence or the amino acid sequence derivedtherefrom in conjunction with the protein-chemical investigationscarried out shows that TNF-BP is a glycosylated polypeptide with 172amino acids, which is converted by proteolytic cleaving after the 11thamino acid into a glycoprotein with 161 amino acids. The following Tableshows the tryptic peptides sequenced and the corresponding amino acidsequences derived from the cDNA sequence:

Fraction Amino acids 12  1-8  1  12-19  8  20-32 14/I  36-48 20  36-5311  54-67 (Amino acids 66-67 had not been correctly determined on thepeptide) 14/II  79-91 26 133-146  5 147-158 27 159-172

The cDNA obtained is the prerequisite for the preparation of recombinantTNF-BP.

As already mentioned, the cDNA initially isolated according to theinvention does not contain the stop codon which could have been expectedfrom analysis of the C-terminus after the codon for Asn-172, but theopen reading frame is continued. The region between Val-183 and Met-204is strongly hydrophobic by nature. This hydrophobic region of 22 aminoacids followed by a portion containing positively charged amino acids(Arg-206, Arg-209) has the typical features of a transmembrane domainwhich anchors proteins in the cell membrane. The protein fractionfollowing in the C-terminus direction on the other hand is stronglyhydrophilic.

The hydrophobicity profile is shown in FIG. 2 (the hydrophobicity plotwas produced using the Mac Molly program (made by Soft Gene Berlin); thewindow size for calculating the values was 11 amino acids. Hydrophobicregions correspond to positive values and hydrophilic regions tonegative values on the ordinates. The abscissa shows the number of aminoacids beginning with the start methionine S1).

The protein structure shows that the DNA coding for the soluble TNF-BPsecreted is part of a DNA coding for a larger protein: this protein hasthe feature of a protein anchored in the cell membrane, contains TNF-BPin a manner typical of extracellular domains and has a substantialportion which is typical of cytoplasmatic domains. Soluble TNF-BP isobviously obtained from this membrane-bound form by proteolytic cleavingjust outside the transmembrane domain.

The structure of the protein coded by the cDNA obtained in conjunctionwith the ability of TNF-BP to bind TNF confirms the assumption thatTNF-BP is part of a cellular surface receptor for TNF the extracellulardomains of which, responsible for the binding of TNF, can be cleavedproteolytically and retrieved in the form of the soluble TNF-BP. (Thepossibility should not be ruled out that, with regard to the operatingcapacity of the receptor, this protein may possibly be associated withone or more other proteins).

For the purposes of the production of TNF-BP on a larger scale, it isadvantageous not to start from the whole cDNA, since the need to cleaveTNF-BP from that part of the protein which represents the membrane-boundpart of the TNF receptor must be borne in mind. Rather, as mentionedhereinbefore, a translation stop codon is expediently inserted after thecodon for Asn-172 by controlled mutagenesis in order to prevent proteinsynthesis going beyond the C-terminal end of TNF-BP. With the cDNA whichis initially obtained according to the invention and which represents apartial sequence of the DNA coding for a TNF receptor, it is possible toobtain the complete receptor sequence by amplifying the missing 3′-end,e.g. by means of modified PCR (RACE=“rapid amplification of cDNA ends”(Frohman, M. A., et al., Proc. Natl. Acad. Sci. 85:8998-9002 (1988)),with the aid of a primer constructed on the basis of a sequence locatedas far as possible in the direction of the 3′-end of the cDNA present.An alternative method is the conventional screening of the cDNA librarywith the available cDNA or parts thereof as probe.

According to the invention, first of all the rat TNF receptor cDNA wasisolated and with a partial sequence therefrom the complete human TNFreceptor cDNA was obtained and brought to expression.

The invention relates to a human TNF receptor and the DNA coding for it.This definition also includes DNAs which code for C- and/or N-terminallyshortened, e.g. processed forms or for modified forms (e.g. by changesat proteolytic cleavage sites, glycosylation sites or specific domainregions) or for fragments, e.g. the various domains, of the TNFreceptor. These DNAs may be used in conjunction with the controlsequences needed for expression as a constituent of recombinant DNAmolecules, to which the present invention also relates, for transformingprokaryotic or eukaryotic host organisms. On the one hand this createsthe prerequisite for preparing the TNF receptor or modifications orfragments thereof in larger quantities by the recombinant method, inorder to make it possible for example to clarify the three-dimensionalstructure of the receptor. On the other hand, these DNAs can be used totransform higher eukaryotic cells in order to allow a study of themechanisms and dynamics of the TNF/receptor interaction, signaltransmission or the relevance of the various receptor domains orsections thereof.

The present invention encompasses the expression of the desired TNFbinding protein in either prokaryotic or eukaryotic cells. Preferredeukaryotic hosts include yeast (especially Saccharomyces), fungi(especially Aspergillus), mammalian cells (such as, for example, humanor primate cells) either in vivo, or in tissue culture.

Yeast and mammalian cells are preferred hosts of the present invention.The use of such hosts provides substantial advantages in that they canalso carry out post-translational peptide modifications includingglycosylation. A number of recombinant DNA strategies exist whichutilize strong promoter sequences and high copy number of plasmids whichcan be utilized for production of the desired proteins in these hosts.

Yeast recognize leader sequences on cloned mammalian gene products andsecrete peptides bearing leader sequences (i.e., pre-peptides).Mammalian cells provide post-translational modifications to proteinmolecules including correct folding or glycosylation at correct sites.

Mammalian cells which may be useful as hosts include cells of fibroblastorigin such as VERO or CHO-K1, and their derivatives. For a mammalianhost, several possible vector systems are available for the expressionof the desired TNF binding protein. A wide variety of transcriptionaland translational regulatory sequences may be employed, depending uponthe nature of the host. The transcriptional and translational regulatorysignals may be derived from viral sources, such as adenovirus, bovinepapilloma virus, simian virus, or the like, where the regulatory signalsare associated with a particular gene which has a high level ofexpression. Alternatively, promoters from mammalian expression products,such as actin, collagen, myosin, etc., may be employed. Transcriptionalinitiation regulatory signals may be selected which allow for repressionor activation, so that expression of the genes can be modulated. Ofinterest are regulatory signals which are temperature-sensitive so thatby varying the temperature, expression can be repressed or initiated, orare subject to chemical regulation, e.g., metabolite.

The expression of the desired TNF binding protein in eukaryotic hostsrequires the use of eukaryotic regulatory regions. Such regions will, ingeneral, include a promoter region sufficient to direct the initiationof RNA synthesis. Preferred eukaryotic promoters include the promoter ofthe mouse metallothionein I gene (Hamer, D., et al., J. Mol. Appl. Gen.1:273-288 (1982)); the TK promoter of Herpes virus (McKnight, S., Cell31:355-365 (1982)); the SV40 early promoter (Benoist, C., et al., Nature(London) 290:304-310 (1981)); the yeast gal4 gene promoter (Johnston, S.A., et al., Proc. Natl. Acad. Sci. (USA) 79:6971-6975 (1982); Silver, P.A., et al., Proc. Natl. Acad. Sci. (USA) 81:5951-5955 (1984)).

As is widely known, translation of eukaryotic mRNA is initiated at thecodon which encodes the first methionine. For this reason, it ispreferable to ensure that the linkage between a eukaryotic promoter anda DNA sequence which encodes the desired receptor molecule does notcontain any intervening codons which are capable of encoding amethionine (i.e., AUG). The presence of such codons results either inthe formation of a fusion protein (if the AUG codon is in the samereading frame as the desired receptor molecule encoding DNA sequence) ora frame-shift mutation (if the AUG codon is not in the same readingframe as the desired TNF binding protein encoding sequence).

The expression of the TNF binding proteins can also be accomplished inprocaryotic cells. Preferred prokaryotic hosts include bacteria such asE. coli, Bacillus, Streptomyces, Pseudomonas, Salmonella, Serratia, etc.The most preferred prokaryotic host is E. coli. Bacterial hosts ofparticular interest include E. coli K12 strain 294 (ATCC 31446), E. coliX1776 (ATCC 31537), E. coli W3110 (F⁻, lambda⁻, prototrophic (ATCC27325)), and other enterobacteria (such as Salmonella typhimurium orSerratia marcescens), and various Pseudomonas species. The prokaryotichost must be compatible with the replicon and control sequences in theexpression plasmid.

To express the desired TNF binding protein in a prokaryotic cell (suchas, for example, E. coli, B. subtilis, Pseudomonas, Streptomyces, etc.),it is necessary to operably link the desired receptor molecule encodingsequence to a functional prokaryotic promoter. Such promoters may beeither constitutive or, more preferably, regulatable (i.e., inducible orderepressible). Examples of constitutive promoters include the intpromoter of bacteriophage λ, and the bla promoter of the β-lactamasegene of pBR322, etc. Examples of inducible prokaryotic promoters includethe major right and left promoters of bacteriophage λ (P_(L) and P_(R)),the trp, recA, lacZ, lacI, gal, and tac promoters of E. coli, theα-amylase (Ulmanen, I., et al., J. Bacteriol. 162:176-182 (1985)), theσ-28-specific promoters of B. subtilis (Gilman, M. Z., et al., Gene32:11-20 (1984)), the promoters of the bacteriophages of Bacillus(Gryczan, T. J., In: The Molecular Biology of the Bacilli, AcademicPress, Inc., NY (1982)), and Streptomyces promoters (Ward, J. M., etal., Mol. Gen. Genet. 203:468-478 (1986)). Prokaryotic promoters arereviewed by Glick, B. R., (J. Ind. Microbiol. 1:277-282 (1987));Cenatiempo, Y. (Biochimie 68:505-516 (1986)); and Gottesman, S. (Ann.Rev. Genet. 18:415-442 (1984)).

Proper expression in a prokaryotic cell also requires the presence of aribosome binding site upstream from the gene-encoding sequence. Suchribosome binding sites are disclosed, for example, by Gold, L., et al.(Ann. Rev. Microbiol. 35:365-404 (1981)).

The desired TNF binding protein encoding sequence and an operably linkedpromoter may be introduced into a recipient prokaryotic or eukaryoticcell either as a non-replicating DNA (or RNA) molecule, which may eitherbe a linear molecule or, more preferably, a closed covalent circularmolecule. Since such molecules are incapable of autonomous replication,the expression of the desired receptor molecule may occur through thetransient expression of the introduced sequence. Alternatively,permanent expression may occur through the integration of the introducedsequence into the host chromosome.

In one embodiment, a vector is employed which is capable of integratingthe desired gene sequences into the host cell chromosome. Cells whichhave stably integrated the introduced DNA into their chromosomes can beselected by also introducing one or more markers which allow forselection of host cells which contain the expression vector. The markermay complement an auxotrophy in the host (such as leu2, or ura3, whichare common yeast auxotrophic markers), biocide resistance, e.g.,antibiotics, or heavy metals, such as copper, or the like. Theselectable marker gene can either be directly linked to the DNA genesequences to be expressed, or introduced into the same cell byco-transfection.

In a preferred embodiment, the introduced sequence will be incorporatedinto a plasmid or viral vector capable of autonomous replication in therecipient host. Any of a wide variety of vectors may be employed forthis purpose. Factors of importance in selecting a particular plasmid orviral vector include: the ease with which recipient cells that containthe vector may be recognized and selected from those recipient cellswhich do not contain the vector; the number of copies of the vectorwhich are desired in a particular host; and whether it is desirable tobe able to “shuttle” the vector between host cells of different species.

Any of a series of yeast gene expression systems can be utilized.Examples of such expression vectors include the yeast 2-micron circle,the expression plasmids YEP13, YCP and YRP, etc., or their derivatives.Such plasmids are well known in the art (Botstein, D., et al., MiamiWntr. Symp. 19:265-274 (1982); Broach, J. R., In: The Molecular Biologyof the Yeast Saccharomyces: Life Cycle and Inheritance, Cold SpringHarbor Laboratory, Cold Spring Harbor, N.Y., p. 445-470 (1981); Broach,J. R., Cell 28:203-204 (1982)).

For a mammalian host, several possible vector systems are available forexpression. One class of vectors utilize DNA elements which provideautonomously replicating extrachromosomal plasmids, derived from animalviruses such as bovine papilloma virus, polyoma virus, adenovirus, orSV40 virus. A second class of vectors relies upon the integration of thedesired gene sequences into the host chromosome. Cells which have stablyintegrated the introduced DNA into their chromosomes may be selected byalso introducing one or more markers which allow selection of host cellswhich contain the expression vector. The marker may provide forprototropy to an auxotrophic host, biocide resistance, e.g.,antibiotics, or heavy metals, such as copper or the like. The selectablemarker gene can either be directly linked to the DNA sequences to beexpressed, or introduced into the same cell by co-transformation.Additional elements may also be needed for optimal synthesis of mRNA.These elements may include splice signals, as well as transcriptionpromoters, enhancers, and termination signals. The cDNA expressionvectors incorporating such elements include those described by Okayama,H., Mol. Cell. Biol. 3:280 (1983), and others.

Preferred prokaryotic vectors include plasmids such as those capable ofreplication in E. coli such as, for example, pBR322, ColE1, pSC101,pACYC 184, πVX. Such plasmids are, for example, disclosed by Maniatis,T., et al. (In: Molecular Cloning, A Laboratory Manual, Cold SpringHarbor Press, Cold Spring Harbor, N.Y. (1982)). Bacillus plasmidsinclude pC194, pC221, pT127, etc. Such plasmids are disclosed byGryczan, T. (In: The Molecular Biology of the Bacilli, Academic Press,NY (1982), pp. 307-329). Suitable Streptomyces plasmids include pIJ101(Kendall, K. J., et al., J. Bacteriol. 169:4177-4183 (1987)), andStreptomyces bacteriophages such as øC31 (Chater, K. F., et al., In:Sixth International Symposium on Actinomycetales Biology, AkademiaiKaido, Budapest, Hungary (1986), pp. 45-54). Pseudomonas plasmids arereviewed by John, J. F., et al. (Rev. Infect. Dis. 8:693-704 (1986)),and Izaki, K. (Jpn. J. Bacteriol. 33:729-742 (1978)).

Once the vector or DNA sequence containing the constructs has beenprepared for expression, the DNA constructs may be introduced into anappropriate host. Various techniques may be employed, such as protoplastfusion, calcium phosphate precipitation, electroporation or otherconventional techniques. After the fusion, the cells are grown in mediaand screened for appropriate activities. Expression of the sequenceresults in the production of the TNF binding protein.

The TNF binding proteins of the invention may be isolated and purifiedfrom the above-described recombinant molecules in accordance withconventional methods, such as extraction, precipitation, chromatography,affinity chromatography, electrophoresis, or the like. By the term“substantially pure” is intended TNF binding proteins which aresubstantially one major band by SDS-PAGE polyacrylamide electrophoresisand which contain only minor amounts of other proteins which wouldnormally contaminate a whole cell lysate containing native TNF receptorprotein, as evidenced by the presence of other minor bands.

The recombinant TNF receptor (or fragments or functional derivativesthereof) can be used to investigate substances for their interactionwith TNF or the TNF receptor or their influence on the signaltransmission induced by TNF. Such screenings (usingproteins/fragments/variants or suitably transformed higher eukaryoticcells) create the prerequisite for the identification of substanceswhich substitute TNF, inhibit the bonding thereof to the receptor orthose which are capable of blocking or intensifying the mechanism ofsignal transmission initiated by TNF.

One possible method of discovering agonists and antagonists of TNF orthe TNF receptor is in the establishment of high capacity screening. Asuitable cell line, preferably one which does not express endogenoushuman TNF receptor, is transformed with a vector which contains the DNAcoding for a functional TNF receptor and optionally modified from thenatural sequence. The activity of agonists or antagonists can beinvestigated in screening of this kind by monitoring the response to theinteraction of the substance with the receptor using a suitable reporter(altered enzyme activity, e.g. protein kinase C, or gene activation,e.g. manganese superoxide dismutase, NF-KB). Investigations into themechanisms and dynamics of the TNF/receptor interaction, signaltransmission or the role of the receptor domains in this respect mayalso be carried out, for example, by combining DNA fractions coding forthe extracellular domain of the TNF. receptor (or parts thereof) withDNA fractions coding for various transmembrane domains and/or variouscytoplasmatic domains and bringing them to expression in eukaryoticcells. The hybrid expression products which may be obtained in this waymay be capable of giving conclusive information as to the relevance ofthe various receptor domains, on the basis of any changes in theproperties for signal transduction, so that targeted screening is madeeasier.

The availability of the cDNA coding for the TNF receptor or fractionsthereof is the prerequisite for obtaining the genomic DNA. Understringent conditions, a DNA library is screened and the clones obtainedare investigated to see whether they contain the regulatory sequenceelements needed for gene expression in addition to the coding regions(e.g. checking for promoter function by fusion with coding regions ofsuitable reporter genes). Methods for screening DNA libraries understringent conditions are taught, for example, in EPA 0 174 143,incorporated by reference herein. Obtaining the genomic DNA sequencemakes it possible to investigate the regulatory sequences situated inthe area which does not code for the TNF receptor, particularly in the5′-flanking region, for any possible interaction with known substanceswhich modulate gene expression, e.g. transcription factors or steroids,or possibly discover new substances which might have a specific effecton the expression of this gene. The results of such investigationsprovide the basis for the targeted use of such substances for modulatingTNF receptor expression and hence for directly influencing the abilityof the cells to interact with TNF. As a result, the specific reactionwith the ligands and the resulting effects can be suppressed.

The scope of the present invention also includes DNAs which code forsubtypes of the TNF receptor or its soluble forms, which may possiblyhave properties different from those of the present TNF receptor. Theseare expression products which are formed by alternative splicing andhave modified structures in certain areas, e.g. structures which canbring about a change in the affinity and specificity for the ligand(TNF-α/TNF-β) or a change in terms of the nature and efficiency ofsignal transmission.

With the aid of the cDNA coding for the TNF receptor it is possible toobtain nucleic acids which hybridize with the cDNA or fragments thereofunder conditions of low stringency and code for a polypeptide capable ofbinding TNF or contain the sequence coding for such a polypeptide.

According to a further aspect the invention relates to recombinantTNF-BP, preferably in a secretable form, which constitutes the solublepart of the TNF receptor according to the invention, and the DNA codingfor it. By introducing a DNA construct containing the sequence codingfor TNF-BP with a sequence coding for a signal peptide under the controlof a suitable promoter into suitable host organisms, especiallyeukaryotic and preferably higher eukaryotic cells, it is possible toproduce TNF-BP which is secreted into the cell supernatant.

If a signal peptide is used with regard to the secretion of the protein,the DNA coding for the signal peptide is conveniently inserted beforethe codon for Asp-12 in order to obtain a uniform product.Theoretically, any signal peptide is suitable which guarantees secretionof the mature protein in the corresponding host organism. If necessary,the signal sequence can also be placed in front of the triplet codingfor Leu-1; in this case, it may be necessary to separate the form ofTNF-BP produced by splitting off the peptide which consists of 11 aminoacids at the N-terminus, from the unprocessed or incompletely processedTNF-BP in an additional purification step.

Since the cDNA after the codon for Asn-172, which represents theC-terminus on the basis of C-terminal analysis, does not contain a stopcodon, a translation stop codon is expediently introduced, with respectto the expression of TNF-BP, after the codon for Asn-172, by controlledmutagenesis.

The DNA coding for TNF-BP can be modified by mutation, transposition,deletion, addition or truncation provided that DNAs modified in this waycode for (poly)peptides capable of binding TNF. Such modifications mayconsist, for example, of changing one or more of the potentialglycosylation sites which are not necessary for the biological activity,e.g. by replacing the Asn codon by a triplet which codes for a differentamino acid. With a view to maintaining the biological activity,modifications which result in a change in the disulfide bridges (e.g. areduction in their number) may also be carried out.

The DNA molecules referred to thus constitute the prerequisite forconstructing recombinant DNA molecules, which are also an object of theinvention. With recombinant DNA molecules of this kind in the form ofexpression vectors containing the DNA, optionally suitably modified,which codes for a protein with TNF-BP activity, preferably with apreceding signal sequence, and the control sequences needed forexpression of the protein, it is possible to transform and cultivatesuitable host organisms and obtain the protein.

Just like any modifications to the DNA sequence, host cells or organismssuitable for expression are selected particularly with regard to thebiological activity of the protein in binding TNF. Furthermore, thecriteria which are conventionally applied to the preparation ofrecombinant proteins such as compatibility with the chosen vector,processability, isolation of the protein, expression characteristics,safety and cost aspects are involved in the decision as to the hostorganism. The choice of a suitable vector arises from the host intendedfor transformation. In principle, all vectors which replicate andexpress the DNAs (or modifications thereof) coding for TNF-BP accordingto the invention are suitable.

With respect to the biological activity of the protein, in theexpression of the DNA coding for TNF-BP, particular account should betaken of any relevance of the criteria, found in the natural protein, ofglycosylation and a high proportion of cysteine groups to the propertyof binding TNF. Conveniently, therefore, eukaryotes, particularlysuitable expression systems of higher eukaryotes, are used for theexpression.

Within the scope of the present invention, both transient and permanentexpression of TNF-BP were demonstrated in eukaryotic cells.

The recombinant TNF-BP according to the invention and suitablemodifications thereof which have the capacity to bind TNF can be used inthe prophylactic and therapeutic treatment of humans and animals forindications in which a harmful effect of TNF-α occurs. Since TNF-BP hasalso been shown to have a TNF-β inhibiting activity, it (or theassociated or modified polypeptides) can be used in suitable doses,possibly in a form modified to give a greater affinity for TNF-β, toinhibit the effect of TNF-β in the body.

The invention therefore also relates to pharmaceutical preparationscontaining a quantity of recombinant TNF-BP which effectively inhibitsthe biological activity of TNF-α and/or TNF-β, or a related polypeptidecapable of binding TNF.

Pharmaceutical preparations are particularly suitable for parenteraladministration for those indications in which TNF displays a harmfuleffect, e.g. in the form of lyophilized preparations or solutions. Thesecontain TNF-BP or a therapeutically active functional derivative thereofin a therapeutically active amount, optionally together withphysiologically acceptable additives such as stabilizers, buffers,preservatives, etc.

The dosage depends particularly on the indication and the specific formof administration, e.g. whether it is administered locally orsystemically. The size of the individual doses will be determined on thebasis of an individual assessment of the particular illness, taking intoaccount such factors as the patient's general health, anamnesis, age,weight, sex, etc. It is essential when determining the therapeuticallyeffective dose to take into account the quantity of TNF secreted whichis responsible for the disease as well as the quantity of endogenousTNF-BP. Basically, it can be assumed that, for effective treatment of adisease triggered by TNF, at least the same molar amount of TNF-BP isrequired as the quantity of TNF secreted, and possibly a multiple excessmight be needed.

More specifically, the objective of the invention is achieved asfollows:

The N-terminal amino acid sequence of the highly purified TNF-BP and theamino acid sequences of peptides obtained by tryptic digestion of theprotein were determined.

Moreover, the C-terminus was determined by carboxypeptidase P digestion,derivatization of the amino acids split off and chromatographicseparation. From the peptide sequences obtained by tryptic digestion,with a view to their use in PCR for the preparation of oligonucleotides,regions were selected from the N-terminus on the one hand and from atryptic peptide on the other hand such that the complexity of mixedoligonucleotides for hybridization with cDNA is kept to a minimum. A setof mixed oligonucleotides were prepared on the basis of these tworegions, the set derived from the region located at the N-terminus beingsynthesized in accordance with mRNA, whilst the set derived from thetryptic peptide was synthesized in reverse, so as to be complementary tothe mRNA. In order to facilitate the subsequent cloning of a segmentamplified with PCR, the set of oligonucleotides derived from the trypticpeptide was given a BamHI restriction site. Then λ DNA was isolated fromthe TNF-α induced fibrosarcoma cDNA library and from this a TNF-BPsequence was amplified using PCR. The resulting fragment was cloned andsequenced; it comprises 158 nucleotides and contains the sequence codingfor the tryptic peptide 20 between the two fragments of sequenceoriginating from the primer oligonucleotides.

This DNA fragment was subsequently radioactively labelled and used as aprobe for isolating cDNA clones from the fibrosarcoma library. Theprocedure involved first hybridizing plaques with the probe, separatingphages from hybridizing plaques and obtaining λ DNA therefrom.Individual cDNA clones were subcloned and sequenced; two of thecharacterized clones contained the sequence coding for TNF-BP.

This sequence constitutes part of the sequence coding for a TNFreceptor.

After shortening of the 5′-non-coding region and insertion of a stopcodon after the codon for the C-terminal amino acid of the naturalTNF-BP, the cDNA was inserted in a suitable expression plasmid,eukaryotic cells were transformed therewith and the expression of TNF-BPwas demonstrated using ELISA.

The still outstanding 3′-region of the TNF receptor was obtained bysearching through a rat brain cDNA library from the rat glia tumour cellline C6 using a TNF-BP probe and isolating all the cDNA coding for therat TNF receptor.

The fraction of this cDNA at the 3′-end, which was assumed to correspondto the missing 3′-region behind the EcoRI cutting site of the human TNFreceptor, was used as a probe to search through the HS913T cDNA libraryonce more. A clone was obtained which contains all the DNA coding forthe TNF receptor.

After shortening of the 5′-non-coding region, the cDNA was inserted inan expression plasmid and the expression of human TNF receptor wasdemonstrated in eukaryotic cells by means of the binding ofradioactively labelled TNF.

Northern blot analysis confirmed that the isolated cDNA correspondssubstantially to all the TNF-R mRNA (the slight discrepancy arises fromthe absence of part of the 5′-non-coding region). From this it can beconcluded that the expressed protein is the complete TNF receptor.

The invention is illustrated by means of the Examples which follow.

EXAMPLE 1

Preparation of highly purified TNF-BP

a) Concentration of urine

200 liters of dialyzed urine from uraemia patients, stored in flaskscontaining EDTA (10 g/l), Tris (6 g/l), NaN₃ (1 g/l) and benzamidinehydrochloride (1 g/l) and kept in a refrigerator were concentrated byultrafiltration using a highly permeable haemocapillary filter with anasymmetric hollow fibre membrane (FH 88H, Gambro) down to 4.2 literswith a protein content of 567 g. The concentrated urine was dialyzedagainst 10 mM/l Tris HCl, pH 8. During this procedure, as in thefollowing steps (except reverse phase chromatography), 1 mM/l ofbenzamidine hydrochloride were added in order to counteract proteolyticdigestion. Unless otherwise stated, all the subsequent purificationsteps were carried out at 4° C.

b) Ion exchange chromatography

This step was carried out by charging DEAE Sephacel columns (2.5×40 cm)with samples of concentrated and dialyzed urine containing about 75 g ofprotein. Elution was carried out with 800 ml of an NaCl/10 mM Tris/HClpH 8 gradient, the NaCl concentration being 0 to 0.4 M. The fractionsfrom seven columns contain the TNF-BP with a total protein content of114 g were stored at −20° C.

c) Affinity chromatography

In order to prepare the TNF Sepharose column, rTNF-α (15 mg) in 0.1 MNaHCO3, 1 M NaCl, pH 9 (coupling buffer) was coupled to 1.5 g ofcyanogen bromide-activated Sepharose 4B (Pharmacia). The Sepharose wasswelled in 1 mM HCl and washed with coupling buffer. After the additionof rTNF-α the suspension was left to rotate for 2 hours at ambienttemperature. The excess CNBr groups were blocked by rotation for one anda half hours with 1M ethanolamine, pH 8. The TNF Sepharose was washed afew times alternately in 1M NaCl, 0.1 M sodium acetate pH 8 and 1 MNaCl, 0.1 M boric acid pH 4 and then stored in phosphate-buffered salinesolution with 1 mM benzamidine hydrochloride. The fractions obtainedfrom step b) were adjusted to a concentration of 0.2 M NaCl, 10 mMTris/HCl, pH 8. The TNF-Sepharose was packed into a column and washedwith 0.2 M NaCl, 10 mM Tris HCl, pH 8 and the TNF-BP-containingfractions, corresponding to about 30 g of protein, were applied at athroughflow rate of 10 ml/h and washed exhaustively with 0.2 M NaCl, 10mM Tris HCl, pH 8, until no further absorption could be detected in theeluate at 280 nm. Then TNF-BP was eluted with 0.2 M glycine/HCl, pH 2.5.TNF-BP-containing fractions from 4 separations were combined andlyophilized after the addition of polyethylene glycol (MW 6000) up to afinal concentration of 10 mg/ml. The lyophilized sample was dissolved indistilled water and dialyzed against distilled water. (The dialyzedsample (4 ml) was stored in deep-frozen state).

This purification step further concentrated the product by about 9000times compared with the previous product. SDS-PAGE (carried out asdescribed in preliminary test 2) of the TNF-BP containing fractionsshowed the elution of three main components with molecular weights of28,000, 30,000 and 50,000.

d) Reverse Phase Chromatography

An aliquot amount (1 ml) of the fractions obtained from step c) with theaddition of 0.1% trifluoroacetic acid was applied to a ProRPC HR 5/10column (Pharmacia), connected to an FPLC system (Pharmacia). The columnwas equilibrated with 0.1% trifluoroacetic acid and charged at ambienttemperature with a linear 15 ml gradient of 10 vol % to 50 vol %acetonitrile containing 0.1% trifluoroacetic acid; the through-flow ratewas 0.3 ml/min. Fractions of 0.5 ml were collected and the absorption at280 nm was determined, as well as the activity of the TNF-α bindingprotein, using the competitive binding test as described in Example 5,using 0.01 μl of sample in each case. TNF-BP eluted as a single activitypeak corresponding to a sharp UV absorption peak.

This last purification step brought an increase in specific activity ofabout 29 fold, whilst the total increase in activity compared with thestarting material (concentrated dialysis urine) was about 1.1×106-fold.SDS-PAGE of the reduced and non-reduced samples, carried out asdescribed in preliminary test 2, resulted in a diffuse band, indicatingthe presence of a single polypeptide with a molecular weight of about30,000. The diffused appearance of the band may be due to the presenceof one of more heterogeneous glycosylations and/or a second polypeptidepresent in a smaller amount. The assumption that it might be apolypeptide with the N-terminus found to be a secondary sequence inpreliminary test 3d), which is longer than TNF-BP at the end terminus,was confirmed by the sequence of the cDNA, according to which there is afraction of 11 amino acids between the signal sequence and Asn (position12), the sequence of which coincides with the N-terminal secondarysequence and which is obviously split off from the processed protein.

EXAMPLE 2

SDS polyacrylamide gel electrophoresis (SDS-PAGE)

SDS-PAGE was carried out using the method of Laemmli (Laemmli, U. K.,Nature 227:680-4 (1970)) on flat gels measuring 18 cm long, 16 cm wideand 1.5 mm thick, with 10 pockets, by means of an LKB 2001electrophoresis unit. The protein content of the samples from thepurification steps c) and d) (preliminary test 1) was determined byBio-Rad Protein Assay or calculated from the absorption at 280 nm, anabsorption of 1.0 being recognized to be equivalent to a content of 1 mgTNF-BP/ml.

The samples containing about 25 μg of protein (from preliminary test 1c)or about 5 μg (from 1d) in reduced form (β-mercaptoethanol) andnon-reduced form, were applied to a 3% collecting gel and a 5 to 20%linear polyacrylamide gradient gel. Electrophoresis was carried out at25 mA/gel without cooling. The molecular weight markers used (Pharmacia)were phosphorylase B (MW 94,000), bovine serum albumin (MW 67,000),ovalbumin (MW 43,000), carboanhydrase (MW 30,000), soya bean trypsininhibitor (MW 20,100) and a-lactalbumin (MW 14,400). The gels werestained with Coomassie Blue in 7% acetic acid/40% ethanol anddecolorized in 7% acetic acid/25% ethanol.

The results of the SDS-PAGE showed TNF-BP to be a polypeptide chain witha molecular weight of about 30,000.

EXAMPLE 3

a) Preparation of samples

15 μg of the protein purified according to preliminary test Id) weredesalinated using reverse phase HPLC and further purified. To do this aBakerbond WP C18 column was used (Baker; 4.6×250 mm) and 0.1%trifluoroacetic acid in water (eluant A) or in acetonitrile (eluant B)as the mobile phase. The increase in the gradient was 20 to 68% eluant Bin 24 minutes. Detection was carried out in parallel at 214 nm and 280nm. The fraction containing TNF-BP was collected, dried and dissolved in75 μl of 70% formic acid and used directly for the amino acid sequenceanalysis.

b) Amino acid sequence analysis

The automatic amino acid sequence analysis was carried out with anApplied Biosystems 477 A liquid phase sequenator by on-linedetermination of the phenylthiohydantoin derivatives released, using anApplied Biosystems Analyser, Model 120 A PTH. It gave the followingN-terminal sequence as the main sequence (about 80% of the quantity ofprotein): Asp-Ser-Val-Xaa-Pro-Gln-Gly-Lys-Tyr-Ile-His-Pro-Gln-. Inaddition, the following secondary sequence was detected:Leu-(Val)-(Pro)-(His)-Leu-Gly-Xaa-Arg-Glu-. (The amino acids shown inbrackets could not be clearly identified.)

EXAMPLE 4

SDS-PAGE

The sample was prepared as described in Example 3 with the differencethat the quantity of sample was 10 μg. The sample was taken up in 50 μlof water and divided into 4 portions. One of the four aliquot parts wasreduced in order to determine its purity by SDS-PAGE according to themethod of Laemmli (24) with DTT (dithiothreitol) and separated onminigels (Höfer, 55×80×0.75 mm, 15%); the molecular weight marker usedwas the one specified in Example 2. Staining was carried out using theOakley method (Oakley, B. R., et al., Analyt. Biochem. 105:361-363(1986)). The electropherogram showed a single band as a molecular weightof about 30,000.

EXAMPLE 5

a) Tryptic Peptide Mapping

About 60 μg of the protein purified in Example 1d) was desalinated byreverse phase HPLC and further purified thereby. A Bakerbond WP C18column (Baker; 4.6×250 mm) was used, and 0.1% trifluoroacetic acid inwater (eluant A) or in acetonitrile (eluant B) was used as the mobilephase. The increase in gradient amounted to 20 to 68% eluant B in 24minutes. Detection was carried out in parallel at 214 nm and at 280 nm.The fraction containing TNF-BP (retention time about 13.0 min.) wascollected, dried and dissolved in 60 μl of 1% ammonium bicarbonate.

1% w/w, corresponding to 0.6 μg of trypsin (Boehringer Mannheim) wasadded to this solution and the reaction mixture was incubated for 6hours at 37° C. Then a further 1% w/w of trypsin were added andincubation was continued overnight.

In order to reduce the disulfide bridges, the reaction mixture was thencombined with 60 μl of 6 M urea and with 12 μl of 0.5 M dithiothreitoland left to stand for 2 hours at ambient temperature.

The tryptic cleavage peptides produced were separated by reverse phaseHPLC, using a Delta Pak C18 column (Waters, 3.9×150 mm, 5 μm particlediameter, 100 A pore diameter) at 30° C. and 0.1% trifluoroacetic acidin water (eluant A) or in acetonitrile (eluant B) as the mobile phase.The gradient was increased from 0 to 55% of eluant B in 55 minutes, then55% B was maintained for 15 minutes. The flow rate was 1 ml/min. anddetection was carried out in parallel at 214 nm (0.5 AUFS) and at 280 nm(0.05 AUFS).

b) Sequence analysis of tryptic peptides

Some of the tryptic cleavage peptides of TNF-BP obtained in a) weresubjected to automatic amino acid sequence analysis. The correspondingfraction from reverse phase HPLC were collected, dried and dissolved in75 μl of 70% formic acid. These solutions were used directly forsequencing in an Applied Biosystems 477 A Pulsed Liquid PhaseSequenator. Table 1 contains the results of the sequence analysis of thetryptic peptides (the amino acids shown in brackets could not beidentified with certainty). The letters “Xaa” indicate that at thispoint the amino acid could not be identified. In fraction 8 the aminoacid in position 6 could not be identified. The sequence -Xaa-Asn-Ser-for position 6-8 leads one to suppose that the amino acid 6 is presentin glycosylated form.

In fraction 17 the amino acid in position 6 could not be identifiedeither. The sequence -Xaa-Asn-Ser- (already occurring in fraction 8) forpositions 6-8 leads one to suppose that amino acid 6 is present inglycosylated form. The first 13 amino acids of fraction 17 aresubstantially identical to fraction 8; fraction 17 should thus be apeptide formed by incomplete tryptic cleavage.

It is striking that fraction 21 is identical to positions 7 to 14 offraction 27. Both in fraction 21 and in fraction 27 the sequencesuddenly breaks off after the amino acid asparagine (position 8 or 14),even though no tryptic cleavage can be expected here. This indicatesthat the amino acid asparagine (position 8 in fraction 21 or position 14in fraction 27) could be the C-terminal amino acid of TNF-BP.

It is noticeable that the sequence of fraction 12 which occurs only insmall amounts, is substantially identical to the secondary sequence ofthe N-terminus found in preliminary test 10. The fact that the proteinsof the main and subsidiary sequence could not be separated on ananalytical reverse phase HPLC column (Example 3b) indicated that theprotein with the subsidiary sequence was a form of TNF-BP extended atthe N-terminus, which was largely converted by processing into theprotein with the main sequence.

table 1 Amino acid sequences of the analyzed tryptic peptides of TNF—BPFraction Amino acid sequence 1 Asp-Ser-Val-Cys-Pro-Gln-Gly-Lys 2Xaa-Xaa-Leu-Ser-(Cys)-Ser-Lys 3 Asp-Thr-Val-(Cys)-Gly-(Cys)-Arg 4Glu-Asn-Glu-(Cys)-Val-Ser-(Cys)- Ser-Asn-(Cys)-Lys 5Glu-Asn-Glu-(Cys)-Val-Ser- (Cys)-(Ser)-Asn-(Cys)-Lys-(Lys) 6Tyr-Ile-His-Pro-Gln-Xaa-Asn-Ser -Ile-Xaa-Xaa-Xaa-Lys 11Glu-Cys-Glu-Ser-Gly-Ser-Phe-Thr -Ala-Ser-Glu-Asn-(Asn)-(Lys) 12Leu-Val-Pro-His-Leu-Gly-Asp-Arg 13 Lys-Glu-Met-Gly-Gln-Val-Glu-Ile-Ser-Ser-(Cys)-Thr-Val-Asp-(Arg) 14/I  Gly-Thr-Tyr-Leu-Tyr-Asn-Asp-Cys-Pro-Gly-Pro-Gly-Gln- 14/II (Glu)-Met-Gly-Gln-Val-(Glu)-(Ile)-(Ser)-Xaa-Xaa-Xaa-(Val)-(Asp)- 15 Lys-Glu-Met-Gly-Gln-Val-Glu-Ile-Ser-Ser-(Cys)-Thr-Val-Asp-Arg-Asp- Thr-Val-(Cys)-Gly- 17Tyr-Ile-His-Pro-Gln-Xaa-Asn-Ser -Ile-(Cys)-(Cys)-Thr-Lys-(Cys) His-Lys-Gly-Xaa-Tyr- 20 Gly-Thr-Tyr-Leu-Tyr-Asn-Asp-Cys-Pro-Gly-Pro-Gly-Gln-Asp-Thr-Xaa-Xaa -Arg 21Leu-(Cys)-Leu-Pro-Gln-Ile-Glu- Asn 26 Gln-Asn-Thr-Val-(Cys)-Thr-Xaa-(His)-Ala-Gly-Phe-(Phe)-Leu-(Arg) 27 Ser-Leu-Glu-(Cys)-Thr-Lys-Leu-(Cys)-Leu-Pro-Gln-Ile-Asn

EXAMPLE 6

Analysis of the C-terminus

This analysis was carried out on the principle of the method describedin (Hsieng, S. L., et al., J. Chromatography 447:351-364 (1988)).

About 60 μg of the protein purified in Example 2d were desalinated andthus further purified by reverse phase HPLC. A Bakerbond WP C18 column(Baker; 4.6×250 mm) was used and 0.1% trifluoroacetic acid in water(eluant A) or in acetonitrile (eluant B) was used as the mobile phase.The gradient was increased from 20 to 68% eluant B in 24 minutes.Detection was carried out in parallel at 214 nm and at 280 nm. Thefraction containing TNF-BP (retention time about 13.0 min.) wascollected, dried and dissolved in 120 μl of 10 mM sodium acetate(adjusted to pH 4 with 1 N HCl).

To this solution were added 6 μl of Brij 35 (10 mg/ml in water) and 1.5μl of carboxypeptidase P (0.1 mg/ml in water, Boehringer Mannheim, No.810142). This corresponds to a weight ratio of enzyme to protein of 1 to400 (Frohman, M. A., et al., Proc. Natl. Acad. Sci. 85:8998-9002(1988)).

Immediately after the addition of the enzyme a sample of 20 μl of thereaction mixture was taken and the enzymatic reaction therein wasstopped by acidifying with 2 μl of concentrated trifluoroacetic acid andby freezing at −20° C.

The reaction mixture was left to stand in a refrigerator (about 8° C.)and samples of 20 μl were taken after 10, 20, 60 and 120 minutes. Theremainder of the reaction mixture was left at ambient temperature foranother 120 minutes. Immediately after being taken, all the samples wereacidified by the addition of 2 μl of concentrated trifluoroacetic acidand frozen at −20° C., thereby interrupting the enzymatic reaction.

Parallel to the sample mixture described, containing about 60 μg ofTNF-BP, a reagent double blind control was set up under identicalconditions but with no protein added.

After the last sample had been taken all the samples were dried for 30minutes in a Speed Vac Concentrator, mixed with 10 μl of a solution of 2parts of ethanol, 2 parts of water and 1 part of triethylamine(=“Redrying solution” of the Picotag amino acid analysis system ofMessrs. Waters) and briefly dried again. Then the samples were eachmixed with 20 μl of the derivatization reagent(7:1:1:1=ethanol:water:triethylamine:phenylisothiocyanate; Picotagsystem) in order to derivatize the amino acids split off from theC-terminus, then left to stand for 20 minutes at ambient temperature andthen dried for 1 hour in a Speed Vac Concentrator.

In order to analyze the derivatized amino acids the samples weredissolved in 100 μl of “Sample Diluent” (Picotag system made by Waters).Of these solutions, 50 μl was analyzed by reverse phase HPLC (column,mobile phase and gradient according to the original specifications ofthe Picotag system made by Waters). The chromatograms of the samples andreagent double blind controls were compared with the chromatogram of asimilarly derivatized mixture (100 pmol/amino acid) of standard aminoacids (Messrs. Beckman).

As can be seen from the quantitative results of the Picotag amino acidanalysis (Table 2), asparagine is very likely the C-terminal amino acidof TNF-BP. Apart from asparagine, glutamic acid and a smaller amount ofisoleucine were also detected after 240 minutes' reaction. Quantities ofother amino acids significantly above the reagent double blind valuecould not be found even after 240 minutes reaction. This result(-Ile-Glu-Asn as the C-terminus) confirms the supposition made from theN-terminal sequencing of the tryptic peptides 21 and 27, to the effectthat the amino acids identified at the C-terminus in thesepeptides-Ile-Glu-Asn (Example 5b)—constitute the C-terminus of TNF-BP.

TABLE 2 Quantitative evaluation of the Picotag amino acid analysis afterreaction of carboxypeptidase P with TNF-BP Integrator units for theamino acids Reaction Glutamic time Isoleucine acid Asparagine  0 — — —10 — — — 20 — —  83.304 60 — — 168.250 120  — — 319.470 240  85.53752.350 416.570

Methods used in Examples 7 to 21:

In the Examples which follow, standard molecular biological methods wereused unless expressly stated otherwise, which can be found in therelevant textbooks or which correspond to the conditions recommended bythe manufacturers. To simplify the description of the Examples whichfollow, frequently recurring methods or designations are abbreviated:

“Cutting” or “digestion” of DNA refers to the catalytic cleaving of theDNA using restriction endonucleases (restriction enzymes) at sitesspecific to them (restriction sites). Restriction endonucleases arecommercially available and are used under the conditions recommended bythe manufacturers (buffer, bovine serum albumin (BSA) as carrierprotein, dithiothreitol (DTT) as antioxidant). Restriction endonucleasesare designated by a capital letter, usually followed by small lettersand normally a Roman numeral. The letters depend on the microorganismfrom which the restriction endonuclease in question was isolated (e.g.:Sma I: Serratia marcescens). Usually, about 1 μg of DNA is cut with oneor more units of the enzyme in about 20 μl of buffer solution. Normally,an incubation period of 1 hour at 37° C. is used, but this can be variedin accordance with the manufacturer's instructions for use. Aftercutting, the 5′-phosphate group is sometimes removed by incubation withalkaline phosphatase from calves intestines (CIP). This serves toprevent an undesirable reaction of the specific site in a subsequentligase reaction (e.g. circularization of a linearized plasmid withoutthe insertion of a second DNA fragment). Unless otherwise stated, DNAfragments are normally not dephosphorylated after cutting withrestriction endonucleases. Reaction conditions for incubation withalkaline phosphatase can be found for example in the M13 Cloning andSequencing Handbook (Amersham, PI/129/83/12). After the incubationprotein is removed by extraction with phenol and chloroform and the DNAis precipitated from the aqueous phase by the addition of ethanol.

“Isolation” of a specific DNA fragment means the separation of the DNAfragments obtained by restriction digestion, e.g. on a 1% agarose gel.After electrophoresis and rendering the DNA visible in UV light bystaining with ethidium bromide (EtBr) the desired fragment is located bymeans of molecular weight markers which had been applied and bound byfurther electrophoresis on DE 81 paper (Schleicher and Schull). The DNAis washed by rinsing with low salt buffer (200 mM NaCl, 20 mM TrispH=7.5, 1 mM EDTA) and then eluted with a high salt buffer (1 M NaCl, 20mM Tris pH=7.5, 1 mM EDTA). The DNA is precipitated by the addition ofethanol.

“Transformation” means the introduction of DNA into an organism so thatthe DNA can be replicated therein, either extrachromosomally orchromosomally integrated. Transformation of E. coli follows the methodspecified in the M13 Cloning and Sequencing Handbook (Amersham,PI/129/83/12).

“Sequencing” of a DNA means the determination of the nucleotidesequence. To do this, first of all the DNA which is to be sequenced iscut with various restriction enzymes and the fragments are introducedinto suitably cut M13 mp8, mp9, mp18 or mp19 double stranded DNA, or theDNA is fragmented by ultrasound, the ends repaired and the sizeselectedfragments introduced into Sma I cut, dephosphorylated M13 mp8 DNA(Shotgun method). After transformation of E. coli JM 101, singlestranded DNA is isolated from recombinant M13 phages in accordance withthe M13 Cloning and Sequencing Handbook (Amersham, PI/129/83/12) andsequenced by the dideoxy method (Sanger et al., Proc. Natl. Acad. Sci.74:5463-5467 (1977)). As an alternative to the use of the klenowfragment of E. coli DNA polymerase I it is possible to use T7-DNApolymerase (“Sequenase,” made by United States Biochemical Corporation).The sequence reactions are carried out in accordance with the manual“Sequenase: Step-by-Step Protocols for DNA Sequencing With Sequenase”(Version 2.0).

Another method of sequencing consists in cloning the DNA which is to besequenced into a vector which carries, inter alia, a replication originof a DNA single-strand phage (M13, fl) (e.g. Bluescribe or BluescriptM13 made by Stratagene). After transformation of E. coli JM101 with therecombinant molecule, the transformants can be infected with a helperphage, e.g. M13K07 or R408 made by Promega). As a result, a mixture ofhelper phages and packaged, single-stranded recombinant vector isobtained. The sequencing template is worked up analogously to the M13method. Double-stranded plasmid DNA is denatured by alkali treatment anddirectly sequenced in accordance with the above-mentioned sequencinghandbook.

The sequences were evaluated using the computer programs originallydeveloped by R. Staden (Staden, R., Nucleic Acid Res. 10:4731-4751(1982)) and modified by Ch. Pieler (Pieler Ch., Dissertation,Universität Wien (1987)). “Ligating” refers to the process of formingphosphodiester bonds between two ends of double strand DNA fragments.Usually, between 0.02 and 0.2 μg of DNA fragments in 10 μl are ligatedwith about 5 units of T4DNA ligase (“ligase”) in a suitable buffersolution (Maniatis, T., et al., Molecular Cloning A laboratory Manual.Cold Spring Harbor Laboratory, p. 474 (1982)). “Excising” of DNA fromtransformants refers to the isolation of the plasmid DNA from bacteriaby the alkaline SDS method, modified according to Birnboim and Doly,leaving out the lysozyme. The bacteria are used from 1.5 to 50 ml ofculture.

“Oligonucleotides” are short polydeoxynucleotides which are chemicallysynthesized. The Applied Systems Synthesizer Model 381A is used forthis. The oligonucleotides are worked up in accordance with the Model381A User Manual (Applied Biosystems). Sequence primers are useddirectly without any further purification. Other oligonucleotides arepurified up to a chain length of 70 by the OPC method(OPC=Oligonucleotide purification column, Applied Biosystems, ProductBulletin, January 1988). Longer oligonucleotides are purified bypolyacrylamide gel electrophoresis (6% acrylamide, 0.15% bisacrylamide,6 M urea, TBE buffer) and after elution from the gel, desalinated over aG-25 sepharose column.

EXAMPLE 7

Preparation of TNF-BP-specific hybridization probes

The oligonucleotides were selected, with a view to using them to amplifycDNA, by PCR:

a) From the N-terminal amino acid sequence of the TNF-binding protein(main sequence, obtained from preliminary test 3 and Example 5, fraction1)

Asp-Ser-Val-Cys-Pro-Gln-Gly-Lys-Tyr-Ile-His- Pro-Gln-

a heptapeptide region was selected which permits the lowest possiblecomplexity of a mixed oligonucleotide for hybridizing to cDNA: these areamino acids 6 to 12. In order to reduce the complexity of the mixedoligonucleotide, four mixed oligonucleotides were prepared each having acomplexity of 48. The oligonucleotides were prepared in the direction ofthe mRNA and are thus oriented towards the 3′ end of the sequence andare identical to the non-coding strand of the TNF-BP gene:

Gln-Gly-Lys-Tyr-Ile-His-Pro 5′CAA GGT AAA TAT ATT CAT CC 3′TNF-BP #3/1EBI-1639     G       G   C   C                     A5′CAA GGC AAA TAT ATT CAT CC 3′TNF-BP #3/2 EBI-1640    G       G   C   C                     A 5′CAA GGA AAA TAT ATT CAT CC3′TNF-BP #3/3 EBI-1641     G       G   C   C                     A5′CAA GGG AAA TAT ATT CAT CC 3′TNF-BP #3/4 EBI-1642    G       G   C   C                     A

b) From the amino acid sequence of a tryptic peptide (fraction 11 of thetryptic digestion) of the amino acid sequence

Glu-Cys-Glu-Ser-Gly-Ser-Phe-Thr-Ala-Ser-(Glu/Cys)-Asn-Asn-Lys (cf.Example 5)

a peptide region was selected and another set of mixed oligonucleotideswere synthesized:

-Phe-Thr-Ala-Ser-Glu-Asn-Asn-Lys                  Cys TNF-BP #4/5(EBI-1653): 3′AAA TGA CGG AGA CTC TTG TTG TT CCTAGGG 5′    G   G   T   T   T         T TNF-BP #4/6 (EBI-1654):3′AAA TGA CGG TCA CTC TTG TTG TT CCTAGGG 5′     G   G   T   T   T        T TNF-BP #4/7 (EBI-1657):3′AAA TGA CGG AGA ACA TTG TTG TT CCTAGGG 5′     G   G   T   T   T        T TNF-BP #4/8 (EBI-1658):3′AAA TGA CGG TCA ACA TTG TTG TT CCTAGGG 5′     G   G   T   T   T        T

The oligonucleotides were synthesized complementarily to mRNA and arethus oriented towards the 5′ end of the sequence. In order to allowefficient cloning of the amplified DNA fragment following the PCR, aBamHI linker was also provided at the 5′ end of the oligonucleotides. Iffor example oligonucleotides TNF-BP Nos. 4/5-8 together with TNF-BP No.3/1-4 are used for the PCR on the entire λ DNA of a library, any DNAfragment which results can be subsequently cut with BamHI. The partneroligonucleotides yield a straight end at the 5′ terminus andconsequently the fragment can be cloned into the SmaI-BamHI sites of asuitable vector.

Each mixed oligonucleotide TNF-BP No. 4/5 to 8 is a mixture of 48individual nucleotides and does not take into account a few codons,namely:

Thr ACG Ala GCG and GCT Ser TCG and TCC Asn AAT

In the case of GCT the possibility that the triplet CGG complementary toGCC (Ala) can be effective by forming a G-T bridge is taken intoconsideration, while in the case of TCG (Ser) and AAT (Asn) the sameapplies with regard to AGT and TTG, respectively.

ACG, GCG and TCG are extremely rare codons (CG rule) and are thereforenot taken into consideration.

EXAMPLE 8

Amplification of a partial sequence coding for TNF-BP from a cDNAlibrary

a) Isolation of λ-DNA of a cDNA library

The cDNA library was prepared using the method described in EP-A1-0293567 for the human placental cDNA, with the difference that the startingmaterial used was 109 fibrosarcoma cells of the cell line HS 913 T,which had been grown by stimulation with human TNF-α (10 ng/ml). Insteadof λ gt10, λ gt11 was used (cDNA synthesis: Amersham RPN 1256; EcoRIdigested λ gt11 arms: Promega Biotech; in vitro packaging of the ligatedDNA: Gigapack Plus, Stratagene).

5 ml of the phage supernatant of the amplified cDNA library of the humanfibrosarcoma cell line HS913T in λ gt11 were mixed with 0.5 μg of RNaseA and 0.5 μg of DNase I and incubated for 1 hour at 37° C. The mixturewas centrifuged for 10 minutes at 5000×g, the supernatant was freed fromprotein by extraction with phenol and chloroform and the DNA wasprecipitated from the aqueous phase by the addition of ethanol. Theλ-DNA was dissolved in TE buffer (10 mM Tris pH 7.5; 1 mM EDTA).

b) PCR amplification of a TNF-BP sequence from a cDNA library

For the application of PCR (Saiki et al., Science 239:487-491 (1988)) toDNA from the HS913T cDNA library, 16 individual reactions were carriedout, in each of which one of the 4 mixed oligonucleotides EBI-1639,EBI-1640, EBI-1641, EBI-1642 were used as first primers and one of thefour mixed oligonucleotides EBI-1653, EBI-1654, EBI-1657 and EBI-1658was used as the second primer. Each of these mixed oligonucleotidescontains 48 different oligonucleotides of equal length.

Amplification by means of PCR took place in 50 μl reaction volume,containing 250 ng of λ-DNA from the cDNA library, 50 mM KCl, 10 mM TrispH=8.3, 1.5 mM MgCl₂, 0.01% gelatine, 0.2 mM of each of the 4deoxynucleoside triphosphates (dATP, dGTP, dCTP, dTTP), 200 pmol of eachof first and second primer and 1.25 units of Taq polymerase[Perkin-Elmer Cetus]. To prevent evaporation the solution was coatedwith a few drops of mineral oil (0.1 ml) the PCR was carried out in aDNA Thermal Cycler (Perkin Elmer Cetus) as follows: the samples wereheated to 94° C. for 5 minutes in order to denature the DNA, and thensubjected to 40 amplification cycles. One cycle consisted of 40 seconds'incubation at 94° C., 2 minutes incubation at 55° C. and 3 minutesincubation at 72° C. At the end of the last cycle the samples wereincubated at 72° C. for a further 7 minutes to ensure that the lastprimer lengthening had been completed. After cooling to ambienttemperature, the samples were freed from protein with phenol andchloroform and the DNA was precipitated with ethanol.

5 μl of each of the 16 PCR samples were applied to an agarose gel andthe length of the amplified DNA fragments was determined afterelectrophoretic separation. The most intense DNA band, a fragment 0.16kb long, could be seen in the PCR samples which had been amplified withthe oligonucleotide EBI-1653 as the first primer and one of theoligonucleotides EBI-1639, EBI-1640, EBI-1641 or EBI-1642 as the secondprimer. Since the sample amplified with the pair of primers EBI-1653 andEBI-1642 contained the largest amount of this 0.16 kb DNA fragment, thissample was selected for further processing.

EXAMPLE 9

Cloning and Sequencing of a DNA fragment obtained by PCR amplification

The PCR product of primers EBI-1642 and EBI-1653 obtained was cut withBamHI and subsequently separated by electrophoresis in an agarose gel(1.5% NuSieve GTG agarose plus 1% Seakem GTG agarose, FMC Corporation)according to size. The main band, a DNA fragment 0.16 kb long, waselectroeluted from the gel and precipitated with ethanol. This DNAfragment was ligated with BamHI/SmaI cut plasmid pUC18 (Pharmacia) andE. coli JM101 was transformed with the ligation mixture. The plasmidsprepared by the mini-preparation method were characterized by cuttingwith the restriction enzymes PvuII and EcoRI-BamHI and subsequentelectrophoresis in agarose gels. The plasmid pUC18 contains two cuttingsites for PvuII which flank the polycloning site in a 0.32 kb DNAfragment. Very short DNA inserts in the polycloning site of the plasmidcan be made visible more easily in agarose gel after cutting with PvuIIsince the length is extended by 0.32 kb. By cutting with EcoRI and BamHIthe DNA fragment ligated into the plasmid vector cut with BamHI andSmaI, including some base pairs of the polylinker sequence, can beobtained. A clone with the desired insert has been designated pTNF-BP3B.The entire DNA insert of this clone was sequenced after subcloning of anEcoRI-BamHI fragment in M13mp18 (Pharmacia) by the modified dideoxymethod using sequenase (United States Biochemical Corporation).

Analysis of the PCR-amplified DNA gave the following sequence (only thenon-coding strand is shown, and above it the derived amino acidsequence):

                  5                  10Gln Gly Lys Tyr Ile His Pro Gln Asn Asn Ser Ile CysCAG GGG AAA TAT ATT CAC CCT CAA AAT AAT TCG ATT TGC    15                  20                  25Cys Thr Lys Cys His Lys Gly Thr Tyr Leu Tyr Asn AspTGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC           30                 35Cys Pro Gly Pro Gly Gln Asp Thr Asp Cys Arg Glu CysTGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT40                 45                 50Glu Ser Gly Ser Phe Thr Ala Ser Glu Asn Asn LysGAG AGC GGC TCC TTC ACA GCC TCA GAA AAC AAC AAG GAT CC

The first 20 and last 29 nucleotides (underlined script) correspond tothe sequences of the primer oligonucleotides EBI-1642 and the complementof EBI-1653, respectively. Amino acids 38 to 43 confirm the remainingsequence of the tryptic peptide 11. Furthermore, the DNA fragmentproduced by PCR contains the sequence of the peptide of fraction 20 ofthe tryptic digestion (amino acids 20 to 34, underlined). This showsthat the clone pTNF-BP3B was derived from a cDNA which codes for TNFbinding protein. pTNF-BP3B therefore constitutes a probe, e.g. forsearching for TNF-BP cDNAs in cDNA libraries.

EXAMPLE 10

Isolation of TNF-BP cDNA clones

About 720,000 phages of the HS913T cDNA library in λ gt11 were plated onE. coli Y1088 (ΔlacU169, pro::Tn5, tonA2, hsdR, supE, supF, metB, trpR,F-,λ -, (pMC9)) (about 60,000 phages per 14.5 cm petri dish, LB-agar: 10g/l tryptone, 5 g/l of yeast extract, 5 g/l of NaCl, 1.5% agar, platingin top agarose: 10 g/l of tryptone, 8 g/l of NaCl, 0.8% agarose). Twonitrocellulose filter extracts were prepared from each plate. Thefilters were prewashed (16 hours at 65° C.) in:

50 mM Tris/HCl pH = 8.0 1 M NaCl 1 mM EDTA 0.1% SDS

The filters were pre-hybridized for two hours at 65° C. in:

6x SSC (0.9M NaCl, 0.09 M trisodium citrate) 5x Denhardt's (0.1% Ficoll,0.1% polyvinylpyrrolidone, 0.1% BSA (=bovine serum albumin) 0.1% SDS

Preparation of the radioactively labelled probe: pTNF-BP 3B was doublycut with BamHI and EcoRI and the approximately 0.16 kb insert wasisolated. 0.6 μg of the insert in 32 μl were denatured at 100° C. andprimed with 60 pmol each of EBI-1642 and EBI-1653 by cooling to 80° C.over 10 minutes and rapid cooling in ice water. After the addition of

10 μl α-³²P-dCTP (100 μCi, 3.7 MBq) 5 μl 10x priming buffer (0.1 MTris/HCl pH = 8.0, 50 mM MgCl₂) 2 μl 1 mM dATP, dGTP, dTTP 1 μl PolIK(Klenow fragment of E. coli DNA polymerase 1, 5 units)

Incubation was carried out for 90 minutes at ambient temperature. Afterheat inactivation (10 minutes at 70° C.), the non-incorporatedradioactivity was removed by chromatography on Biogel P6DG (Biorad) inTE buffer (10 mM Tris/HCl pH=8, 1 mM EDTA). 65×10⁶ cpm wereincorporated. The hybridization of the filters was carried out in atotal volume of 80 ml of 6×SSC/5× Denhardt's/0.1% SDS plusheat-denatured hybridizing probe for 16 hours at 65° C. The filters werewashed twice for 30 minutes at ambient temperature in 6×SSC/0.01% SDSand once for 45 minutes at ambient temperature in 2×SSC/0.01% SDS andthree times for 30 minutes at 65° C. in 2×SSC/0.01% SDS. The filterswere dried in air and then exposed to Amersham Hyperfilm for 16 hoursusing an intensifier film at −70° C. In all, 30 hybridizing plaques wereidentified (λ-TNF-BP No. 1-30). The regions with the hybridizing plaqueswere pricked out as precisely as possible and the phages were eluted in300 μl of SM buffer plus 30 μl of chloroform. By plaque purification(plating of about 200 phages per 9 cm petri dish on the second passage,or about 20 phages per 9 cm petri dish on the third passage, filterextracts doubled, preparation, hybridization and washing (as describedin the first search) 25 hybridizing phages were finally separated(λ-TNF-BP #1-10, 12-24, 29, 30).

Preparation of the recombinant λ-DNA from the clones λ-TNF-BP Nos. 13,15, 23, 30:

2×10⁶ phages were plated on E. coli Y1088 in top agarose (10 g/ltryptone, 8 g/l NaCl, 0.8% agarose) (14.5 cm petri dish) with LB agarose(1.5% agarose, 0.2% glucose, 10 mM MgSO4, 10 g/l tryptone, 5 g/l yeastextract, 5 g/l NaCl) and incubated at 37° C. for 6 hours. After theplates had been cooled (30 minutes at 4° C.) they were coated with 10 mlof Adiluent (10 mM Tris/HCl pH=8.0, 10 mM MgCl₂, 0.1 mM EDTA) and elutedfor 16 hours at 4° C. The supernatant was transferred into 15 ml Corextest tubes and centrifuged for 10 minutes at 15000 rpm and at 4° C.(Beckman J2-21 centrifuge, JA20 rotor). The supernatant was decantedinto 10 ml polycarbonate test tubes and centrifuged at 50000 rpm at 20°C. until ω²t=3×10¹⁰ (Beckman L8-70, 50 Ti rotor). The pellet wasresuspended in 0.5 ml of λ-diluent and transferred into Eppendorf testtubes (1.4 ml). After the addition of 5 μg of RNase A and 0.5 μg DNaseIand incubation at 37° C. for 30 minutes and the addition of 25 μl of 0.5M EDTA, 12.5 μl of 1 M Tris/HCl pH=8.0, 6.5 μl of 20% SDS, incubationwas continued at 70° C. for 30 minutes. The λ-DNA was purified byphenol/chloroform extraction and precipitated with ethanol. Finally, theDNA was dissolved in 100 μl of TE buffer.

EXAMPLE 11

Subcloning and sequencing of TNF-BP cDNA clones 15 and 23

In order to characterize the cDNAs of the clones λTNF-BP15 andλTNF-BP23, which showed the strongest signals during hybridization, thecDNA inserts were cut out of the λ-DNA with EcoRI, then afterelectrophoretic separation eluted from an agarose gel and precipitatedwith ethanol. The DNA fragments of 1.3 kb (from λTNF-BP15) and 1.1 kb(from λTNF-BP23) were cut with EcoRI and ligated with alkalinephosphatase from calves' intestines dephosphorylated plasmid vectorpT7/T3α-18 (Bethesda Research Laboratories) with T4 DNA ligase and E.coli JM101 was transformed. From individual colonies of bacteria whichshowed no blue staining after selection on agarose plates withampicillin and X-gal, plasmid DNA was prepared in a mini preparationprocess and the presence and orientation of the cDNA insert wasdetermined by cutting with EcoRI and HindIII. Plasmids which containedthe EcoRI insert of the phages λTNF-BP15 or λTNF-BP23 oriented in such away that the end corresponding to the 5′-end of the mRNA is facing theT7 promotor were designated pTNF-BP15 and pTNF-BP23, respectively. TheEcoRI inserts of λTNF-BP15 and λTNFBP23 were also ligated in M13mp19vector which had been cut with EcoRI and dephosphorylated, and E. coliJM101 was transformed. From a few randomly selected M13 clones,single-stranded DNA was prepared and used as the basis for sequencing bythe dideoxy method. On M13 clones which contained the cDNA inserts inthe opposite orientation, both DNA strands were fully sequenced usingthe universal sequencing primer and specifically synthesizedoligonucleotide primers which bind to the cDNA insert.

The complete nucleotide sequence of 1334 bases of the cDNA insert ofλTNF-BP15 or pTNF-BP15 is shown in FIGS. 1A-1C. Bases 1-6 and 1328-1334correspond to the EcoRI linkers which had been added to the cDNA duringthe preparation of the cDNA library. The nucleotide sequence of the cDNAinsert of λTNF-BP23 corresponds to that of λTNF-BP15 (bases 22-1100),flanked by EcoRI linkers.

The clone λTNF-BP30 was also investigated; its sequence corresponds toλTNF-BP15, except that the sequence has a deletion of 74 bp (nucleotide764 to 837).

EXAMPLE 12

Construction of the expression plasmid pAD-CMV1 and pADCMV2

From parts of the expression plasmids pCDM8 (Seed and Aruffo, Proc.Natl. Acad. Sci. 84:8573-8577 (1987); Seed , B. Nature 329:840-842(1987)); Invitrogen), pSV2gptDHFR20 (EP-A1 0321 842) and the plasmidBluescript SK+ (Short, J. M., et al., Nucl. Acids Res. 11:5521-5540(1988); Stratagene) a new plasmid was constructed which has amulti-cloning site for the directed insertion of heterologous DNAsequences and which can be replicated in E. coli by means of ampicillinresistance with a high copy number. The intergenic region of M13 makesit possible to produce single-stranded plasmid DNA by superinfection ofthe transformed bacteria with a helper phage (e.g. R408 or M13K07) tofacilitate sequencing and mutagenesis of the plasmid DNA. The T7promotor which precedes the multi-cloning site makes it possible toprepare RNA transcripts in vitro. In mammalian cells heterologous genesare expressed, driven by cytomegalovirus (CMV) promotor/enhancer(Boshart, M., et al., Cell 41:521-530 (1985)). The SV40 replicationorigin makes it possible, in suitable cell lines (e.g. SV40 transformedcells such as COS-7, adenovirus transformed cell line 293 (ATCCCRL1573)), to carry out autonomous replication of the expression plasmidat high copy numbers and thus at high rates in transient expression. Forpreparing permanently transformed cell lines and subsequently amplifyingthe expression cassette by means of methotrexate, a modified hamsterminigene is used (promotor with coding region and the first intron) fordihydrofolate reductase (DHFR) as the selection marker.

a) Preparation of the vector and promotor sections by PCR

The plasmid Bluescript SK+was linearized with HindIII and 5 ng of DNAwas used in a 100 μl PCR mixture (reaction buffer: 50 mM KCl, 10 mMTris-Cl pH=8.3, 1.5 mM MgCl₂, 0.01% (w/v) gelatine, 0.2 mM of the fourdeoxynucleotide triphosphates (dATP, dGTP, dCTP, dTTP), 2.5 units of Taqpolymerase per 100 μl. The primers used were 50 pmol of the syntheticoligonucleotides EBI1786 (5′-GGAATTCAGCCTGAATGGCGAATGGG-3′; binds justoutside the M13 ori-region in Bluescript position 475, independently ofthe M13 ori-orientation) and EBI-1729 (5′-CCTCGAGCGTTGCTGGCGTTTTTCC-3′;binds to Bluescript at position 1195 in front of ori, corresponds to thestart of the Bluescript sequence in pCDM8, 6 bases 5′ yield XhoI). After5 minutes denaturing at 94° C. PCR was carried out over 20 cycles (40seconds at 94° C., 45 seconds at 55° C., 5 min at 72° C., Perkin ElmerCetus Thermal Cycler). The oligonucleotides flank the intergenic regionof M13 or the replication origin (ori) with the intermediate gene forβ-lactamase. At the same time, at the end of the replication origin anXhoI cutting site is produced and at the other end an EcoRI cuttingsite. The reaction mixture was freed from protein by extraction withphenol/chloroform and the DNA was precipitated with ethanol. The DNAobtained was cut with XhoI and EcoRI and after electrophoresis in anagarose gel a fragment of 2.3 kb was isolated.

5 ng of plasmid pCDM8 linearized with SacII was amplified by PCR withthe oligonucleotides EBI-1733 (5′GGTCGACATTGATTATTGACTAG-3′; binds toCMV promotor region (position 1542) of pCDM8, corresponding to position1 in pAD-CMV, SalI site for cloning) and EBI-1734(5′GGAATTCCCTAGGAATACAGCGG-3′; binds to polyoma origin of 3′SV40 polyAregion in pCDM8 (position 3590)) under identical conditions to thosedescribed for Bluescript SK+. The oligonucleotides bind at the beginningof the CMV promotor/enhancer sequence and produce an SalI cutting site(EBI-1733) or bind to the end of the SV40 poly-adenylation site andproduce an EcoRI cutting site (EBI-1734). The PCR product was cut withSalI and EcoRI and a DNA fragment of 1.8 kb was isolated from an agarosegel.

The two PCR products were ligated with T4 DNA ligase, E. coli HB101transformed with the resulting ligation product and plasmid DNA wasamplified and prepared using standard methods. The plasmid of thedesired nature (see FIGS. 3A-3B) was designated pCMV-M13. The SV40replication origin (SV40 ori) was isolated from the plasmidpSV2gptDHFR20 (EP-A1 0321842). To do this, this plasmid was doubly cutwith HindIII and PvuII and the DNA ends were blunted by subsequenttreatment with the large fragment of the E. coli DNA polymerase (klenowenzyme) in the presence of the four deoxynucleotide triphosphates. A0.36 kb DNA fragment thus obtained was isolated from an agarose gel andligated into pCMV-M13 linearized with EcoRI. A plasmid obtained aftertransformation of E. coli HB101, with the SV40 ori in the sameorientation as the β-lactamase gene and the CMV promotor, was designatedpCMV-SV40. The construction of this plasmid is shown in FIGS. 3A-3B.

b) Mutagenesis of the DHFR gene

In order to prepare an expression plasmid with a versatile multicloningsite, two restriction enzyme cutting sites were removed from the DHFRminigene by directed mutagenesis and three such sites were removed bydeletion. To do this, a 1.7 kb BglII fragment from the plasmidpSV2gptDHFR20, containing the entire coding region of the hamster DHFRgene, was cloned into the BglII site of the plasmid pUC219 (IBI) and theplasmid pUCDHFR was obtained. E. coli JM109 (Stratagene) cellstransformed with pUCDHFR were infected with an approximately 40-foldexcess of the helper phage R408 (Stratagene) and shaken in LB medium for16 hours at 37° C. Single stranded plasmid DNA was isolated from thebacterial supernatant.

Controlled mutagenesis was carried out in two successive steps, usingthe in vitro mutagenesis system RPN1523 (Amersham). The EcoRI sitelocated at the beginning of Exon 2 was destroyed by exchanging a basefrom GAATTC to GAGTTC. This base exchange does not result in any changein the coded amino acid sequence and furthermore corresponds to thenucleotide sequence in the natural murine DHFR gene (McGrogan, M., etal., J. Biol. Chem. 260:2307-2314 (1985); Mitchell, P. J., et al., Mol.Cell. Biol. 6:425-440 (1986)). An oligonucleotide (Antisenseorientation) of the sequence 5′-GTACTTGAACTCGTTCCTG-3′ (EBI-1751) wasused for the mutagenesis. A plasmid with the desired mutation wasprepared as single strand DNA as described above and the PstI sitelocated in the first intron was removed by mutagenesis with theoligonucleotide EBI-1857 (Antisense orientation,5′-GGCAAGGGCAGCAGCCGG-3′) from CTGCAG into CTGCTG. The mutations wereconfirmed by sequencing and the resulting plasmid was designatedpUCDHFR-Mut2.

The 1.7 kb BglII fragment was isolated from the plasmid pUCDHFR-Mut2 andligated into plasmid pSV2gptDHFR20, doubly cut with BglII and BamHI.After transformation of E. coli, amplification and DNA isolation, aplasmid of the desired nature was obtained, which was designatedpSV2gptDHFR-Mut2. By cutting with BamHI, in the 3′-non-coding region ofthe DHFR gene a 0.12 kb DNA fragment following the BglII site wasremoved, which also contains a KpnI cutting site. By linking theoverhanging DNA ends formed with BglII and BamHI, the recognitionsequences for these two enzymes were also destroyed.

The plasmid pCMV-SV40 was doubly cut with EcoRI and BamHI and the DNAends were then blunted with Klenow enzyme. The DNA was purified byextraction with phenol chloroform and ethanol precipitation, thendephosphorylated by incubation with alkaline phosphatase and the 4.4 kblong vector DNA was isolated from an agarose gel.

The plasmid pSV2gptDHFR-Mut2 (FIGS. 4A-4B) was doubly cut with EcoRI andPstI and the DNA ends were blunted by 20 minutes' incubation at 11° C.with 5 units of T4 DNA polymerase (50 mM Tris HCl pH=8.0, 5 mM MgCl₂, 5mM dithiothreitol, 0.1 mM of each of the four deoxynucleotidetriphosphates and 50 μg/ml of bovine serum albumin). The 2.4 kb long DNAfragment with the mutated DHFR gene was isolated from an agarose gel andligated with the pCMV-SV40 prepared as described above. A plasmidobtained after transformation of E. coli and containing the DHFR gene inthe same orientation as the CMV promotor was designated pCMV-SV40DHFR.

In the last step the 0.4 kb stuffer fragment after the CMV promotor,which originated from the original plasmid pCDM8, was exchanged for amulticloning site. To do this, the plasmid pCMV-SV40DHFR was doubly cutwith HindIII and XbaI and the vector part was isolated from an agarosegel. The multicloning site formed from the two oligonucleotides EBI-1823(5′-AGCTTCTGCAGGTCGACATCGATGGATCCGGTACCTCGAGCGGCCGCGAATTCT-3′) andEBI-1829 (5′-CTAGAGAATTCGCGGCCGCTCGAGGTACCGGATCCATCGATGTCGACCTGCAGA-3′),contains, including the ends which are compatible for cloning inHindIII-XbaI, restriction cutting sites for the enzymes PstI, SalI,ClaI, BamHI, KpnI, XhoI, NotI and EcoRI.

1 μg of each of the two oligonucleotides was incubated for 1 hour at 37°C. in 20 μl of reaction buffer (70 mM Tris-Cl pH=7.6, 10 mM MgCl₂, 5 mMdithiothreitol, 0.1 mM ATP) with 5 units of T4 polynucleotide kinase inorder to phosphorylate the 5′ ends. The reaction was stopped by heatingto 70° C. for 10 minutes and the complementary oligonucleotides werehybridized with one another by incubating the sample for a further 10minutes at 56° C. and then slowly cooling it to ambient temperature. 4μl of the hybridized oligonucleotides (100 ng) were ligated with about100 ng of plasmid vector and E. coli HB101 was transformed. A plasmidwhich was capable of being linearized with the enzymes of themulticloning site (with the exception of NotI) was designed pAD-CMV1. Ofa number of clones tested, it was not possible to identify any one theplasmids which could be cut with NotI. Sequencing always showed thedeletion of some bases within the NotI recognition sequence.

In the same way, the expression plasmid pAD-CMV2 which contains therestriction cutting sites within the multicloning site in the reverseorder was obtained with the oligonucleotide pair EBI-1820(5′-AGCTCTAGAGAATTCGCGGCCGCTCGAGGTACCGGATCCATCGATGTCGACCTGCAGAAGCTTG-3′)and EBI-1821(5′-CTAGCAAGCTTCTGCAGGTCGACATCGATGGATCCGGTACCTCGAGCGGCCGCGAATTCTCTAG-3′). The plasmid pAD-CMV2 was obtained which was capable ofbeing linearized with all the restriction enzymes, including NotI.

The nucleotide sequence of the 6414 bp plasmid pADCMV1 (FIG. 5B) isshown in full in FIGS. 6A-6E.

The sections of the plasmid (specified in the numbering of the bases)correspond to the following sequences:

  1-21 EBI-1733, beginning of CMV enhancer-promotor (from CDM8)  632-649T7 promotor  658-713 Multicloning site (HindIII to XbaI from EBI-1823,EBI-1829)  714-1412 SV40 intron and poly-adenylation site (from CDM8)1413-2310 5′-non-coding region and promotor of the hamster DHFR gene(from pSV2gptDHFR20) 2311-2396 Hamster DHFR: Exon 1 2516 A to T mutationdestroys PstI site in DHFR intron 1 2701-3178 DHFR Exons 2-6 (codingregion) 2707 A to G mutation destroys EcoRI site 3272-3273 Deletionbetween BglII and BamHI in DHFR3′- non-coding region 3831 End of DHFRgene (from pSV2gptDHFR20) 3832-4169 SV40 ori (from pSV2gptDHFR20)4170-4648 M13 ori (from pBluescript SK+) 4780-5640 β-lactamase (codingregion) 6395-6414 EBI-1729, end of the pBluescript vector sequence

The preparation of the plasmids pAD-CMV1 and pAD-CMV2 is shown in FIGS.5A-5B.

EXAMPLE 13

Construction of the plasmid pADTNF-BP for the expression of the solubleform of TNF-BP

In order to prepare the secreted form of TNF-BP by the direct method, atranslation stop codon was inserted in the cDNA coding for part of theTNF receptor (see Example 11; hereinafter designated TNF-R cDNA) afterthe codon of the C-terminal amino acid of the natural TNF-BP (AAT,Asn-172; corresponding to position 201 in FIG. 9A). In this way theprotein synthesis is broken off at this point and makes it possible tosecrete TNF-BP directly into the cell supernatant without having toundergo a subsequent reaction, which might possibly be rate determiningof proteolytic cleaving of sections of the TNF receptor located in theC-terminal direction.

At the same time as the stop codon was inserted by PCR the 5′-non-codingregion of the TNF-R cDNA was shortened in order to remove thetranslation start codon of another open reading frame (bases 72-203 inFIG. 9A), which is located 5′ from that of the TNF-R, and a BamHI orEcoRI cutting site is inserted at the 5′ or 3′-end of the cDNA.

100 ng of plasmid pTNF-BP15 linearized with XmnI (see Example 11) wereamplified with 50 pmol of oligonucleotides EBI-1986 (Sense,5′-CAGGATCCGAGTCTCMCCCTCAAC-3′) and EBI-1929 (Antisense,5′-GGGAATTCCTTATCMTTCTCMTCTGGGGTAGGCACAACTTC-3′; insertion of two stopcodons and an EcoRI site) in a 100 μl PCR mixture over 10 cycles. Thecycle conditions were 40 minutes at 94° C., 45 seconds at 55° C. and 5minutes at 72° C. After the last cycle incubation was continued for afurther 7 minutes at 72° C. and the reaction was stopped by extractingwith phenol chloroform. The DNA was precipitated with ethanol and thendoubly cut with BamHI and EcoRI. The resulting 0.75 kb DNA fragment wasisolated from an agarose gel and cloned into plasmid pT7/T3α-19 (BRL)doubly cut with BamHI and EcoRI. One of the plasmids obtained, which wasfound to have the desired sequence, when the entire insert wassequenced, was designated pTNF-BP.

pTNF-BP was cut with BamHI and EcoRI and the 0.75 kb DNA insert wascloned into the expression plasmid pAD-CMV1 cut with BamHI and EcoRI. Aplasmid obtained with the desired composition was designated PADTNF-BP(FIG. 7A).

EXAMPLE 14

Construction of the plasmid pADBTNF-BP for the expression of the solubleform of TNF-BP

For another variant of an expression plasmid for the production ofsecreted TNF-BP, the 5′-non-coding region of TNF-R cDNA was exchangedfor the 5-non-coding region of human β-globin mRNA. The reason for thiswas the finding that the nucleotide sequence immediately before thetranslation start codon of the TNF-R sequence differs significantly fromthe concensus sequence found for efficient expression of eukaryoticgenes (Kozak, 1987), whereas the 5′-non-coding region of the β-globinmRNA corresponds extremely well to this concensus sequence (Lawn et al.,1980). By means of the oligonucleotide EBI-2452(5′-CACAGTCGACTTACATTTGCTTCTGACACAACTGTGTTCACTAGCAACCTCAAACAGACACCATGGGCCTCTCCACCGTGC-3′), which contained after a SalIrestriction cutting site the authentic 5′-noncoding sequence,corresponding to the human β-globin mRNA sequence, followed by 20 basesof the coding region of TNF-BP, the TNF-R sequence was modified in aPCR. 100 ng of plasmid pTNF-BP linearized with EcoRI were amplified in100 μl of reaction mixture with 50 pmol each of the oligonucleotidesEBI-2452 and EBI-1922 (Antisense, 5′-GAGGCTGCAATTGAAGC3′; binds to thehuTNF-R sequence at position 656) in 20 PCR cycles (40 seconds at 94°C., 45 seconds at 55° C., 90 seconds at 72° C.). After the PCR producthas been purified by extraction with phenol-chloroform and ethanolprecipitation, the DNA was doubly cut with SalI and BglII and theresulting 0.51 kb DNA fragment was isolated from an agarose gel. Thecorresponding part of the TNF-R sequence was removed from the plasmidpTNF-BP by cutting with SalI and BglII, the 3.1 kb long plasmid portionwas isolated from an agarose gel and ligated with the 0.51 kb long PCRproduct. After transformation of E. coli, seven of the resultingplasmids were sequenced. One of these plasmids contained precisely thedesired sequence. This plasmid was designated pBTNF-BP. The entireSalI-EcoRI insert of pBTNF-BP was cloned into the similarly cutexpression plasmid pAD-CMV1 and the resulting plasmid was designatedpADBTNF-BP (FIG. 7B).

EXAMPLE 15

Isolation of rat TNF-R cDNA clones

First of all, rat brain cDNA was prepared analogously to the HS913T cDNAlibrary (see Example 4) from the rat Glia tumour cells lines C6 (ATCCNo. CCL107) in λ-gt11.

600,000 phages of the rat brain cDNA library in λgt11 were screened byhybridization as described in Example 6. The probe used was the purifiedEcoRI insert of pTNF-BP30 (cf. Example 6). About 100 ng of DNA wereradioactively labelled with 1 μg of random hexamer primer instead of thespecific oligonucleotides, as described in Example 6, using [α-³²P]dCTP.25×10⁶ cpm were incorporated. Hybridization of the filters was carriedout under the same conditions as in Example 6. The filters were washedtwice for 30 minutes at ambient temperature in 2×SSC/0.1% SDS and threetimes for 30 minutes at 65° C. in 2×SSC/0.1% SDS and twice for 30minutes at 65° C. in 0.5×SSC/0.5% SDS. The air dried filters were thenexposed to Kodak XAR X-ray film for 16 hours using an intensifier filmat −70° C. A total of 10 hybridizing plaques were identified andseparated by plaque purification. After plaque purification had beencarried out three times, three A clones (λ-raTNF-R Nos. 3, 4 and 8) werefinally separated out and the phage DNA was prepared as described.

The length of the cDNA insert was determined after cutting the λ-DNAwith EcoRI and separation in an agarose gel at 2.2 kb for the clonesraTNF-R3 and raTNF-R8 and 2.1 kb for clone raTNF-R4. The EcoRI insertsof clones λraTNF-R3 and 8 were cloned into similarly cut M13mp19 and theDNA sequence was determined with universal sequencing primers andspecifically synthesized oligonucleotide primers.

The complete nucleotide sequence of raTNF-R8 is shown in FIGS. 8A-8B.The first and last seven bases correspond to the EcoRI linkers which hadbeen added during the preparation of the cDNA library.

EXAMPLE 16

Isolation of a clone containing the complete cDNA coding for the humanTNF receptor

The complete cDNA of the rat TNF-R made it easier to search for themissing 3′ part of human TNF-R cDNA. The probe used for thehybridization was the 0.4 kb long PCR product of the primers EBI-2316(5′-ATTCGTGCGGCGCCTAG-3′; binds to TNF-R with the 2nd base of EcoRI,breaks off at the TNF-R cDNA) and EBI-2467 (5′GTCGGTAGCACCAAGGA-3′;binds about 400 bases before poly-A to cDNA clone, corresponds toposition 1775 in raTNF-R) with λraTNF-R8 as starting material. This DNAfragment corresponds to the region of rat TNF-R cDNA which had beenassumed to follow the internal EcoRI site in human TNF-R.

2.5×10⁶ cpm of the raTNF-R probe were used to hybridize 600,000 plaquesof the HS913T cDNA library. The hybridization conditions corresponded tothose specified in Example 10. The filters were washed twice for 30minutes at ambient temperature in 2×SSC/0.1% SDS and twice for 30minutes at 65° C. in 2×SSC/0.1% SDS, dried in the air and exposed toKodak XAR X-ray film using an intensifier film for a period of 3 days at−70° C. Six positive plaques were identified purified to two furtherrounds of plaques and λ-DNA was prepared (ATNF-R Nos. 2, 5, 6, 8, 11 and12). After the λ-DNA had been cut with EcoRI all the clones had a DNAband about 0.8 kb long. λ-TNF-R2 and 11 additionally contained an EcoRIfragment of 1.3 kb. The two EcoRI inserts from λTNF-R2 were subclonedinto the EcoRI site of plasmid pUC218 (IBI) and then sequenced. Thesequence of the 1.3 kb EcoRI fragment corresponded to that of cDNA clonepTNF-BP15, the 0.8 kb EcoRI fragment corresponds to the 3′ part of TNF-RmRNA and contains, in front of the EcoRI linker sequence, a poly-A tailwith 16 A residues. λTNF-R2 therefore contains the complete codingregion for human TNF-R, shown in FIGS. 9A-9B.

EXAMPLE 17

Construction of the plasmids pADTNF-R and pADBTNF-R for expression ofthe entire human TNF receptor

First of all, as described in Example 13 for pTNF-BP or pADTNF-BP, aplasmid was constructed in which the 5′ noncoding region of pTNF-BP15had been shortened, but, unlike the plasmids described in Example 13,the 3′-end of pTNF-BP15 had been kept. For this purpose, under identicalconditions to those described in Example 13, pTNF-BP15 was amplifiedwith PCR using the oligonucleotide EBI-1986 and the M13-40 universalprimer (5′-GTTTTCCCAGTCACGAC-3′). The PCR product was doubly cut withBamHI and EcoRI and cloned into the plasmid pT7/T3α-19. One of theplasmids obtained was designated pTNF-BP15B.

pTNF-BP15B was cut with BamHI and EcoRI and the 1.26 kb DNA insert wascloned into expression plasmid pAD-CMV1 cut with BamHI and EcoRI. Aplasmid of the desired composition thus obtained was designatedpAOTNFBP15.

This plasmid was linearized with EcoRI and the 0.8 kb EcoRI fragmentisolated from λTNF-R2 was cloned into the cutting site. Aftertransformation of E. coli, a few randomly isolated plasmids werechecked, by cutting with various restriction enzymes, for the correctorientation of the EcoRI fragment used. A plasmid designated pADTNF-R(FIG. 7C) was investigated more accurately for correct orientation bysequencing the insert, starting from the 3′-end of the inserted cDNAwith the oligonucleotide EBI-2112 (5′GTCCAATTATGTCACACC-3′), which bindsto the plasmid pAD-CMV1 and its derivatives after the multicloning site.

Another expression plasmid in which the 5′-noncoding region of the TNF-Ris exchanged for that of β-globin was constructed. Plasmid pADBTNF-BPwas cut completely in order to remove the 1.1 kb BglII fragment, the DNAends were then dephosphorylated with calves' intestinal alkalinephosphatase and the plasmid vector (5.9 kb) with the β-globin5′-noncoding region of the β-globin gene and the 5′ part of the TNF-Rcoding region was isolated from an agarose gel. Plasmid pADTNF-R was cutwith BglII and the 2.5 kb DNA fragment containing the 3′ section of theTNF-R cDNA as far as the promotor region of the following DHFR gene, wasisolated from an agarose gel and cloned into the plasmid vector whichhad been prepared beforehand. A plasmid obtained after transformation ofE. coli having the BglII fragment inserted in the correct orientationwas designated pADBTNF-R (FIG. 7D).

EXAMPLE 19

Expression of soluble TNF-BP in eukaryotic cell lines

a) ELISA test

In this Example TNF-BP was detected by the ELISA test as follows:

96 well microtitre plates were coated in each well with 50 μl of 1:3000diluted polyclonal rabbit serum (polyclonal rabbit antibodies, preparedby precipitation of antiserum with ammonium sulphate, finalconcentration 50% saturation) against natural TNF-BP for 18 hours at 4°C., washed once with 0.05% Tween 20 in PBS and free binding sites wereblocked with 150 to 200 μl of 0.5% bovine serum albumin, 0.05% Tween 20in PBS (PBS/BSS/Tween) for one hour at ambient temperature. The wellswere washed once with 0.05% Tween 20 in PBS and 50 μl of cellsupernatant or known quantities of natural TNF-BP (see Tables 3 and 4)and 50 μl of a 1:10,000-fold dilution of a polyclonal mouse serumagainst TNF-BP was applied and incubated for two hours at ambienttemperature. Then the wells were washed three times with 0.05% Tween 20in PBS and 50 μl of rabbit anti-mouse Ig-peroxidase conjugate (DakoP161; 1:5000 in PBS/BSA/Tween) were added and incubation was continuedfor a further two hours at ambient temperature. The wells were washedthree times with Tween/PBS and the staining reaction was carried outwith orthophenylenediamine (3 mg/ml) and Na-perborate (1 mg/ml) in0.067M potassium citrate, pH 5.0, 100 μl per well, for 20 minutes atambient temperature away from the light. After the addition of 100 μl of4N H2S04 the color intensity at a wavelength of 492 nm was measuredphotometrically in a microfilm plate photometer.

b) Transient expression of soluble TNF-BP in eukaryotic cell lines

About 106 cells (COS-7) per 80 mm petri dish were mixed with 10% heatinactivated fetal calves' serum 24 hours before transfection inRPMI-1640 medium and incubated at 37° C. in a 5% CO2 atmosphere. Thecells were separated from the petri dish using a rubber spatula andcentrifuged for 5 minutes at 1200 rpm at ambient temperature (Heraeusminifuge, swing-out rotor 3360), washed once with 5 ml of serum-freemedium, centrifuged for 5 minutes at 1200 rpm and suspended in 1 ml ofmedium mixed with 250 μg/ml of DEAE dextran and 10 μg of plasmid DNA(see Table 3), purified by carrying out CsCl density gradientcentrifugation twice). The cells were incubated for 40 minutes at 37°C., washed once with 5 ml of medium containing 10% calves' serum andsuspended in 5 ml of medium with 100 μg/ml of chloroquin. The cells wereincubated for one hour at 37° C., washed once with medium and incubatedwith 10 ml of fresh medium at 37° C. After 72 hours the cell supernatantwas harvested and used to detect the secreted TNF-BP.

TABLE 3 Cell line COS-7 without plasmid <5 ng/ml pADTNF-BP 7.5 ng/mlpADBTNF-BP 146 ng/ml

c) Preparations of cell lines which permanently produce TNF-BP

The dihydrofolate reductase (DHFR)-deficient hamster ovarial cell lineCHO DUKX BII (Urlaub and Chasin, 1980) was transfected with plasmidpADBTNF-BP by calcium phosphate precipitation (Current Protocols inMolecular Biology, 1987). Four thickly grown cell culture flasks (25cm², 5 ml of culture medium per flask) were transfected with 5 μg ofDNA; after four hours incubation at 37° C. the medium was removed andreplaced by 5 ml of selection medium (MEM alpha medium with 10% dialyzedfetal calves' serum). After incubation overnight the cells were detachedusing trypsin solution; the cells from each flask were divided betweentwo 96-well tissue culture plates (100 μl per well in selection medium).Fresh medium was added at about weekly intervals. After about four weekscell clones could be observed in 79 wells. The supernatants were testedfor TNF-BP activity by the ELISA test. 37 supernatants showed activityin ELISA. The results of the ELISA test of some positive clones areshown in Table 4.

TABLE 4 Absorption Sample at 492 nm TNF-BP Standard  1 ng/ml 0.390  10ng/ml 1.233 100 ng/ml 1.875 Culture medium 0.085 (negative control)Clone A1G3 0.468 A2F5 0.931 A3A12 0.924 A4B8 0.356 A5A12 0.806 A5B100.915 A5C1 0.966

EXAMPLE 20

RNA analysis (Northern Blot) of the Human TNF receptor

1 μg of poly-A⁺ RNA (isolated from HS913T (fibrosarcoma)), placenta andspleen were separated by electrophoresis in a 1.5% vertical agarose gel(10 mM Na phosphate buffer pH=7.0, 6.7% formaldehyde). The size markerused was a kilobase ladder radioactively labelled by a fill-in reactionwith (α-³²P)dCTP and Klenow enzyme (Bethesda Research Laboratories). Theformaldehyde was removed from the gel by irrigation and the RNA wastransferred in 20× SSC to a nylon membrane (Genescreen plus,NEN-DuPont). The RNA was covalently bonded on the membrane by UVirradiation (100 seconds). The membrane was prehybridized for 2 hours at65° C. in Church buffer (Church and Gilbert, 1984) (0.5 M NaphosphatepH=7.2, 7% SDS, 1 mM EDTA) and hybridized for 19 hours at 65° C. infresh Church buffer with 3×10⁶ cpm P-32 labelled DNA probe (EcoRI insertof pTNF-BP30). The filter was washed three times for 10 minutes atambient temperature in washing buffer (40 mM Na phosphate pH=7.2, 1%SDS) and then four times for 30 minutes at 65° C. in washing buffer andexposed to Kodak XAR X-ray film for 18 hours using an intensifier filmat −70° C.

The autoradiogram (FIG. 10) shows a singular RNA band with a length of2.3 kb for the human TNF receptor in the analyzed tissues or cell lineHS913T.

EXAMPLE 21

Expression of the TNF receptor

For transient expression 5-10×10⁷ COS-7 cells were incubated for 40minutes with 10 μg of pADTNF-R plasmid DNA in a solution containing 250μg/ml of DEAE dextran and 50 μg/ml of chloroquin. pADCMV-1-DNA was usedas control. After transfection the cells were washed and then culturedfor 48 hours. The expression of the TNF receptor was demonstrated by thebinding ¹²⁵I-TNF. For the binding tests the cells were washed, incubatedfor one hour at 4° C. with 10 mg of ¹²⁵I-TNF (specific radioactivity38,000 cpm/ng) with or without a 200 fold excess of unlabelled TNF andthe radioactivity bound to the cells was measured in a gamma-counter.The specific binding in the control sample was 2062 cpm and in thesamples transformed with TNF receptor DNA it was 6150 cpm (the valuesare expressed as the average bound cpm; the standard deviationdetermined from parallel tests is taken into account. The non-specificbackground in the presence of unlabelled TNF was subtracted from thevalues).

We claim:
 1. An isolated DNA molecule coding for a polypeptide having the ability to bind to TNF, wherein said polypeptide is selected from the group consisting of: A) a polypeptide comprising the amino acid sequence: R² asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn,

or a C- and/or N-terminally shortened sequence thereof, wherein R² is absent or is a polypeptide which can be cleaved in vivo; and B) a polypeptide comprising the amino acid sequence: R² asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr,

or a C- and/or N-terminally shortened sequence thereof, wherein R² is absent or is a polypeptide which can be cleaved in vivo; C) a polypeptide comprising the amino acid sequence of A or B with at least one conservative amino acid substitution; D) a polypeptide comprising the amino acid sequence of A or B with at least one amino acid substitution at a glycosylation site; E) a polypeptide comprising the amino acid sequence of A or B with at least one amino acid substitution at a proteolytic cleavage site; and F) a polypeptide comprising the amino acid sequence of A or B with at least one amino acid substitution at a cysteine residue.
 2. A DNA according to claim 1, wherein said polypeptide includes a methionine at the amino-terminus.
 3. A DNA according to claim 1, wherein said polypeptide includes at least one additional amino acid at the carboxyl-terminus.
 4. A nucleic acid that hybridizes to an isolated DNA molecule complementary to the DNA defined in claim 1 under conditions of moderate stringency and which codes for a polypeptide having the ability to bind to TNF.
 5. A vector comprising a DNA sequence defined in claim
 1. 6. A vector according to claim 5, which is replicable in a prokaryotic a eukaryotic host cell.
 7. A vector according to claim 6, which is replicable in a prokaryotic cell.
 8. A vector according to claim 7, wherein said DNA sequence includes ATG at the amino terminus.
 9. A vector according to claim 7, which is replicable in Escherichia coli.
 10. A vector according to claim 6, which is replicable in a eukaryotic cell.
 11. A vector according to claim 10, which is replicable in a mammalian cell.
 12. A vector according to claim 11, which is replicable in a Chinese Hamster Ovary cell.
 13. A vector according to claim 11, which is replicable in a COS cell.
 14. A recombinant host cell containing a recombinant DNA molecule comprising a DNA coding for a polypeptide having the ability to bind to TNF, wherein said polypeptide is selected from the group consisting of: A) a polypeptide comprising the amino acid sequence: R² asp ser val cys  pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn,

or a C- and/or N-terminally shortened sequence thereof, wherein R² is absent or is a polypeptide which can be cleaved in vivo; B) a polypeptide comprising the amino acid sequence: R² asp ser val cys  pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr,

or a C- and/or N-terminally shortened sequence thereof, wherein R² is absent or is a polypeptide which can be cleaved in vivo; C) a polypeptide comprising the amino acid sequence of A or B with at least one conservative amino acid substitution; D) a polypeptide comprising the amino acid sequence of A or B with at least one amino acid substitution at a glycosylation site; E) a polypeptide comprising the amino acid sequence of A or B with at least one amino acid substitution at a proteolytic cleavage site; and F) a polypeptide comprising the amino acid sequence of A or B with at least one amino acid substitution at a cysteine residue.
 15. A host cell according to claim 14, which is a prokaryotic cell.
 16. A host cell according to claim 15, which is Escherichia coli.
 17. A host cell according to claim 14, which is a eukaryotic cell.
 18. A host cell according to claim 17, which is a mammalian cell.
 19. A host cell according to claim 18, which is a Chinese Hamster Ovary cell.
 20. A host cell according to claim 18, which is a COS cell.
 21. A process for preparing a polypeptide having the ability to bind TNF comprising producing the polypeptide in a host cell according to claim 14 under suitable conditions to express the DNA molecule contained therein to produce the polypeptide, and recovering the polypeptide.
 22. A process according to claim 21, further comprising a step of modifying the recovered polypeptide, wherein the modified polypeptide possesses TNF inhibitory activity.
 23. A process according to claim 22, wherein said step of modifying the recovered polypeptide comprises chemically derivatizing the recovered polypeptide.
 24. A process for making a pharmaceutical composition comprising combining the modified polypeptide of claim 22 with a pharmaceutically acceptable carrier.
 25. A process according to claim 21, wherein said expressed polypeptide is produced as a multimer.
 26. A process according to claim 21, wherein said DNA molecule is contained in an expression vector.
 27. An isolated DNA molecule coding for a polypeptide having the ability to bind to TNF comprising an amino acid sequence as set forth in claim 1 with at least one [intra sequence] intrasequence conservative amino acid substitution in the sequence of claim
 1. 28. An isolated DNA molecule according to claim 27, wherein said polypeptide includes at least one additional amino acid at the amino-terminus, at the carboxyl-terminus, or at both the amino-terminus and at the carboxyl-terminus.
 29. An isolated DNA molecule according to claim 28, wherein said polypeptide includes at least one additional amino acid at the amino-terminus and at the carboxyl-terminus.
 30. An isolated DNA molecule according to claim 28, wherein said polypeptide includes at least one additional amino acid at the amino-terminus.
 31. An isolated DNA molecule according to claim 30, wherein said polypeptide includes a methionine at the amino-terminus.
 32. An isolated DNA molecule according to claim 28, wherein said polypeptide includes at least one additional amino acid at the carboxyl-terminus.
 33. A process for preparing a recombinant host cell containing polypeptide having TNF inhibitory activity comprising producing the polypeptide in a recombinant host cell according to claim 14, under suitable conditions to express the DNA molecule contained therein to produce the polypeptide.
 34. A process according to claim 33, wherein said host cell is a prokaryotic cell.
 35. A process according to claim 34, wherein said host cell is E. Coli.
 36. A process according to claim 33, wherein said host cell is a eukaryotic cell.
 37. A process according to claim 36, wherein said host cell is a mammalian cell.
 38. A process according to claim 37, wherein said host cell is a Chines Hamster Ovary cell.
 39. A process according to claim 37, wherein said host cell is a COS cell.
 40. A process according to claim 33, wherein the DNA molecule comprises promoter DNA, other than the promoter DNA for the native polypeptide having TNF inhibitory activity, operatively linked to the nucleic acid encoding the TNF inhibitor.
 41. A process according to claim 33, wherein the host cell is grown under suitable nutrient conditions to amplify the nucleic acid sequence.
 42. A host cell containing a vector defined in claim
 5. 43. An isolated DNA molecule according to claim 27, wherein said polypeptide includes a methionine at the amino-terminus and said amino acid substitution is at a glycosylation site.
 44. An isolated DNA molecule according to claim 27, wherein said amino acid substitution is at a glycosylation site.
 45. An isolated DNA molecule coding for a polypeptide having the ability to bind to TNF, wherein said DNA is selected from the group consisting of: A) DNA comprising the sequence: R² GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC    CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC    CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA    GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT    GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC    CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA    AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC    ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG    AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC    CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC    AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA    CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC    TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT    AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG    TGC CTA CCC CAG ATT GAG AAT,

or a C- and/or N-terminally shortened sequence thereof, wherein R² is absent or is a DNA comprising a sequence coding for a polypeptide which can be cleaved in vivo; and B) DNA comprising the sequence: R²  GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACC ACA,

or a C- and/or N-terminally shortened sequence thereof, wherein R² is absent or represents DNA coding for a polypeptide which can be cleaved in vivo; C) a DNA sequence of A or B encoding at least one conservative amino acid substitution; D) a DNA sequence of A or B encoding at least one amino acid substitution at a glycosylation site; E) a DNA sequence of A or B encoding at least one amino acid substitution at a proteolytic cleavage site; and F) a DNA sequence of A or B encoding at least one amino acid substitution at a cysteine residue.
 46. An isolated DNA molecule according to claim 45, wherein R² is a DNA comprising a sequence which codes for a polypeptide which can be cleaved in vivo.
 47. An isolated DNA molecule according to claim 45, wherein R² is a DNA comprising the sequence: CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA, or a C- and/or N-terminally shortened sequence thereof.
 48. An isolated DNA molecule according to claim 45, wherein R² is a DNA encoding an amino acid sequence comprising: leu val pro his leu gly asp arg glu lys arg, or a C- and/or N-terminally shortened sequence thereof.
 49. An isolated DNA molecule according to claim 46, wherein R² is a DNA comprising the sequence: R³ CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA, or a C- and/or N-terminally shortened sequence thereof, wherein R³ is a DNA coding for a signal peptide.
 50. An isolated DNA molecule according to claim 46, wherein R² is a DNA encoding an amino acid sequence comprising: R³ leu val pro his leu gly asp arg glu lys arg, or a C- and/or N-terminally shortened sequence thereof, wherein R³ is a DNA coding for a signal peptide.
 51. An isolated DNA molecule according to claim 49, wherein R³ is a DNA comprising the sequence: ATG GGC CTC TCC ACC GTG CCT GAC CTG CTG CTG CCA CTG GTG CTC CTG GAG CTG TTG GTG GAA ATA TAC CCC TCA GGG GTT ATT GGA,

or a C- and/or N-terminally shortened sequence thereof.
 52. An isolated DNA molecule according to claim 49, wherein R³ is a DNA, encoding an amino acid sequence comprising: met gly leu ser thr val pro asp leu leu leu pro leu val leu leu glu leu leu val gly ile tyr pro ser gly val ile gly;

or a C- and/or N-terminally shortened sequence thereof.
 53. An isolated DNA molecule coding for a polypeptide having the ability to bind TNF, wherein said polypeptide is selected from the group consisting of: A) a polypeptide comprising the amino acid sequence: asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn,

or a C- and/or N-terminally shortened sequence thereof; B) a polypeptide comprising the amino acid sequence: leu val pro his leu gly asp arg glu lys arg asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn,

or a C- and/or N-terminally shortened sequence thereof; C) a polypeptide comprising the amino acid sequence: asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr,

or a C- and/or N-terminally shortened sequence thereof; and D) a polypeptide comprising the amino acid sequence: leu val pro his leu gly asp arg glu lys arg asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr,

or a C- and/or N-terminally shortened sequence thereof.
 54. A DNA according to claim 53, wherein said polypeptide includes a methionine at the amino-terminus.
 55. An isolated DNA molecule coding for a polypeptide having the ability to bind TNF selected from the group consisting of: A) a polypeptide comprising the amino acid sequence: met asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn,

or a C- and/or N-terminally shortened sequence thereof; B) a polypeptide comprising the amino acid sequence: met leu val pro his leu gly asp arg glu lys arg asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn,

or a C- and/or N-terminally shortened sequence thereof; C) a polypeptide comprising the amino acid sequence: met asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr,

or a C- and/or N-terminally shortened sequence thereof; D) a polypeptide comprising the amino acid sequence: met leu val pro his leu gly asp arg glu lys arg asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr,

or a C- and/or N-terminally shortened sequence thereof; E) a polypeptide comprising the amino acid sequence: met gly leu ser thr val pro asp leu leu leu pro leu val ,35 leu leu glu leu leu val gly ile tyr pro ser gly val ile gly leu val pro his leu gly asp arg glu lys arg asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn,

or a C- and/or N-terminally shortened sequence thereof; F) a polypeptide comprising the amino acid sequence: met gly leu ser thr val pro asp leu leu leu pro leu val leu leu glu leu leu val gly ile tyr pro ser gly val ile gly leu val pro his leu gly asp arg glu lys arg asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr,

or a C- and/or N-terminally shortened sequence thereof; G) a polypeptide comprising the amino acid sequence: met  gly  leu  ser  thr  val  pro  asp  leu  leu  leu  pro  leu  val leu  leu  glu  leu  leu  val  gly  ile  tyr  pro  ser  gly  val  ile gly  asp  ser  val  cys  pro  gln  gly  lys  tyr  ile  his  pro  gln asn  asn  ser  ile  cys  cys  thr  lys  cys  his  lys  gly  thr  tyr leu  tyr  asn  asp  cys  pro  gly  pro  gly  gln  asp  thr  asp  cys arg  glu  cys  glu  ser  gly  ser  phe  thr  ala  ser  glu  asn  his leu  arg  his  cys  leu  ser  cys  ser  lys  cys  arg  lys  glu  met gly  gln  val  glu  ile  ser  ser  cys  thr  val  asp  arg  asp  thr val  cys  gly  cys  arg  lys  asn  gln  tyr  arg  his  tyr  trp  ser glu  asn  leu  phe  gln  cys  phe  asn  cys  ser  leu  cys  leu  asn gly  thr  val  his  leu  ser  cys  gln  glu  lys  gln  asn  thr  val cys  thr  cys  his  ala  gly  phe  phe  leu  arg  glu  asn  glu  cys val  ser  cys  ser  asn  cys  lys  lys  ser  leu  glu  cys  thr  lys leu  cys  leu  pro  gln  ile  glu  asn,

or a C- and/or N-terminally shortened sequence thereof; H) a polypeptide comprising the amino acid sequence: met gly leu ser thr val pro asp leu leu leu pro leu val leu leu glu leu leu val gly ile tyr pro ser gly val ile gly asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr,

or a C- and/or N-terminally shortened sequence thereof; and I) a polypeptide comprising the amino acid sequence: met gly leu ser thr val pro asp leu leu leu pro leu val leu leu glu leu leu val gly ile tyr pro ser gly val ile gly leu val pro his leu gly asp arg glu lys arg asp ser val cys pro gln gly lys tyr ile his pro gln asn asn ser ile cys cys thr lys cys his lys gly thr tyr leu tyr asn asp cys pro gly pro gly gln asp thr asp cys arg glu cys glu ser gly ser phe thr ala ser glu asn his leu arg his cys leu ser cys ser lys cys arg lys glu met gly gln val glu ile ser ser cys thr val asp arg asp thr val cys gly cys arg lys asn gln tyr arg his tyr trp ser glu asn leu phe gln cys phe asn cys ser leu cys leu asn gly thr val his leu ser cys gln glu lys gln asn thr val cys thr cys his ala gly phe phe leu arg glu asn glu cys val ser cys ser asn cys lys lys ser leu glu cys thr lys leu cys leu pro gln ile glu asn val lys gly thr glu asp ser gly thr thr val leu leu pro leu val ile phe phe gly leu cys leu leu ser leu leu phe ile gly leu met tyr arg tyr gln arg trp lys ser lys leu tyr ser ile val cys gly lys ser thr pro glu lys glu gly glu leu glu gly thr thr thr lys pro leu ala pro asn pro ser phe ser pro thr pro gly phe thr pro thr leu gly phe ser pro val pro ser ser thr phe thr ser ser ser thr tyr thr pro gly asp cys pro asn phe ala ala pro arg arg glu val ala pro pro tyr gln gly ala asp pro ile leu ala thr ala leu ala ser asp pro ile pro asn pro leu gln lys trp glu asp ser ala his lys pro gln ser leu asp thr asp asp pro ala thr leu tyr ala val val glu asn val pro pro leu arg trp lys glu phe val arg arg leu gly leu ser asp his glu ile asp arg leu glu leu gln asn gly arg cys leu arg glu ala gln tyr ser met leu ala thr trp arg arg arg thr pro arg arg glu ala thr leu glu leu leu gly arg val leu arg asp met asp leu leu gly cys leu glu asp ile glu glu ala leu cys gly pro ala ala leu pro pro ala pro ser leu leu arg,

or a C- and/or N-terminally shortened sequence thereof; J) a polypeptide comprising the amino acid sequence of A, B, C, D, E, F, G, H, or I with at least one conservative amino acid substitution; K) a polypeptide comprising the amino acid sequence of A, B, C, D, E, F, G, H, or I with at least one amino acid substitution at a glycosylation site; L) a polypeptide comprising the amino acid sequence of A, B, C, D, E, F, G, H, or I with at least one amino acid substitution at a proteolytic cleavage site; and M) a polypeptide comprising the amino acid sequence of A, B, C, D, E, F, G, H, or I with at least one amino acid substitution at a cysteine residue.
 56. A DNA according to claim 55, wherein said polypeptide includes at least one additional amino acid at the amino-terminus, at the carboxyl-terminus, or at both the amino-terminus and at the carboxyl-terminus.
 57. A DNA according to claim 56, wherein said polypeptide includes at least one additional amino acid at the carboxyl-terminus.
 58. A vector according to claim 10, which is replicable in a yeast cell.
 59. A host cell according to claim 17, which is a yeast cell.
 60. A process according to claim 33, wherein said host cell is a yeast cell.
 61. A nucleic acid which hybridizes with an isolated DNA molecule complementary to the DNA defined in claim 5 under conditions of moderate stringency and which codes for a polypeptide having the ability to bind to TNF.
 62. An isolated DNA molecule according to claim 45, wherein said DNA is selected from the group consisting of: A) DNA comprising the sequence: CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT,

or a C- and/or N-terminally shortened sequence thereof; B) DNA comprising the sequence: CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACC  ACA,

or a C- and/or N-terminally shortened sequence thereof; C) DNA comprising the sequence:                                                GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT,

or a C- and/or N-terminally shortened sequence thereof; and D) DNA comprising the sequence: GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACC ACA,

or a C- and/or N-terminally shortened sequence thereof; E) a DNA sequence of A, B, C or D encoding at least one conservative amino acid substitution; F) a DNA sequence of A, B, C or D encoding at least one amino acid substitution at a glycosylation site; G) a DNA sequence of A, B, C or D encoding at least one amino acid substitution at a proteolytic cleavage site; and H) a DNA sequence of A, B, C or D encoding at least one amino acid substitution at a cysteine residue.
 63. An isolated DNA molecule coding for a polypeptide having the ability to bind to TNF, wherein said DNA coding said polypeptide is selected from the group consisting of: A) DNA comprising the sequence: ATG CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC ATC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT,

or a C- and/or N-terminally shortened sequence thereof; B) DNA comprising the sequence: ATG CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC ATC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACC ACA,

or a C- and/or N-terminally shortened sequence thereof; C) DNA comprising the sequence:                                             ATG GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC ATC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT,

or a C- and/or N-terminally shortened sequence thereof; D) DNA comprising the sequence:                                             ATG GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACC ACA,

or a C- and/or N-terminally shortened sequence thereof; E) DNA comprising the sequence: ATG GGC CTC TCC ACC GTG CCT GAC CTG CTG CTG CCA CTG CTG CTC CTG GAG CTG TTG GTG GGA ATA TAC CCC TCA GGG GTT ATT GGA CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT,

or a C- and/or N-terminally shortened sequence thereof; F) DNA comprising the sequence: ATG GGC CTC TCC ACC GTG CCT GAC CTG CTG CTG CCA CTG GTG CTC CTG GAG CTG TTG GTG GGA ATA TAC CCC TCA GGG GTT ATT GGA CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACC ACA,

or a C- and/or N-terminally shortened sequence thereof; G) DNA comprising the sequence: ATG GGC CTC TCC ACC GTG CCT GAC CTG CTG CTG CCA CTG GTG CTC CTG GAG CTG TTG GTG GGA ATA TAC CCC TCA GGG GTT ATT GGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT,

or a C- and/or N-terminally shortened sequence thereof; H) DNA comprising the sequence: ATG GGC CTC TCC ACC GTG CCT GAC CTG CTG CTG CCA CTG GTG CTC CTG GAG CTG TTG GTG GGA ATA TAC CCC TCA GGG GTT ATT GGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACC ACA,

or a C- and/or N-terminally shortened sequence thereof; and I) DNA comprising the sequence: ATG GGC CTC TCC ACC GTG CCT GAC CTG CTG CTG CCA CTG GTG CTC CTG GAG CTG TTG GTG GGA ATA TAC CCC TCA GGG GTT ATT GGA CTG GTC CCT CAC CTA GGG GAC AGG GAG AAG AGA GAT AGT GTG TGT CCC CAA GGA AAA TAT ATC CAC CCT CAA AAT AAT TCG ATT TGC TGT ACC AAG TGC CAC AAA GGA ACC TAC TTG TAC AAT GAC TGT CCA GGC CCG GGG CAG GAT ACG GAC TGC AGG GAG TGT GAG AGC GGC TCC TTC ACC GCT TCA GAA AAC CAC CTC AGA CAC TGC CTC AGC TGC TCC AAA TGC CGA AAG GAA ATG GGT CAG GTG GAG ATC TCT TCT TGC ACA GTG GAC CGG GAC ACC GTG TGT GGC TGC AGG AAG AAC CAG TAC CGG CAT TAT TGG AGT GAA AAC CTT TTC CAG TGC TTC AAT TGC AGC CTC TGC CTC AAT GGG ACC GTG CAC CTC TCC TGC CAG GAG AAA CAG AAC ACC GTG TGC ACC TGC CAT GCA GGT TTC TTT CTA AGA GAA AAC GAG TGT GTC TCC TGT AGT AAC TGT AAG AAA AGC CTG GAG TGC ACG AAG TTG TGC CTA CCC CAG ATT GAG AAT GTT AAG GGC ACT GAG GAC TCA GGC ACC ACA GTG CTG TTG CCC CTG GTC ATT TTC TTT GGT CTT TGC CTT TTA TCC CTC CTC TTC ATT GGT TTA ATG TAT CGC TAC CAA CGG TGG AAG TCC AAG CTC TAC TCC ATT GTT TGT GGG AAA TCG ACA CCT GAA AAA GAG GGG GAG CTT GAA GGA ACT ACT ACT AAG CCC CTG GCC CCA AAC CCA AGC TTC AGT CCC ACT CCA GGC TTC ACC CCC ACC CTG GGC TTC AGT CCC GTG CCC AGT TCC ACC TTC ACC TCC AGC TCC ACC TAT ACC CCC GGT GAC TGT CCC AAC TTT GCG GCT CCC CGC AGA GAG GTG GCA CCA CCC TAT CAG GGG GCT GAC CCC ATC CTT GCG ACA GCC CTC GCC TCC GAC CCC ATC CCC AAC CCC CTT CAG AAG TGG GAG GAC AGC GCC CAC AAG CCA CAG AGC CTA GAC ACT GAT GAC CCC GCG ACG CTG TAC GCC GTG GTG GAG AAC GTG CCC CCG TTG CGC TGG AAG GAA TTC GTG CGG CGC CTA GGG GTG AGC GAC CAC GAG ATC GAT CGG CTG GAG CTG CAG AAC GGG CGC TGC CTG CGC GAG GCG CAA TAC AGC ATG CTG GCG ACC TGG AGG CGG CGC ACG CCG CGG CGC GAG GCC ACG CTG GAG CTG CTG GGA CGC GTG CTC CGC GAC ATG GAC CTG CTG GGC TGC CTG GAG GAC ATC GAG GAG GCG CTT TGC GGC CCC GCC GCC CTC CCG CCC GCG CCC AGT CTT CTC AGA,

or a C- and/or N-terminally shortened sequence thereof; J) a DNA sequence of A, B, C, D, E, F, G, H, or I encoding at least one conservative amino acid substitution; K) a DNA sequence of A, B, C, D, E, F, G, H, or I encoding at least one amino acid substitution at a glycosylation site; L) a DNA sequence of A, B, C, D, E, F, G, H, or I encoding at least one amino acid substitution at a proteolytic cleavage site; and M) a DNA sequence of A, B, C, D, E, F, G, H, or I encoding at least one amino acid substitution at a cysteine residue. 